DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment and Arguments
Applicant’s remarks and amendments filed 7/29/2025, in response to the non-final rejection mailed 1/30/2025, are acknowledged and have been fully considered.
Applicant’s amendment to the claims is acknowledged. This listing of the claims replaces all prior versions and listings of the claims.
Applicant’s arguments concerning the prior rejections under 35 U.S.C. §§ 112(b) and 112(d) have been fully considered and are persuasive. The claimed subject matter is being interpreted as limited by the explanation in the Applicant’s reply on pg 7, which recites that the “first cells” may be a mixture of different cells, and thus the dependent claims do further limit the “first cells” by reciting particular cell types and specific elements thereof. The rejections under 35 U.S.C. §§ 112(b) and 112(d) are withdrawn.
Any other previous rejection or objection not mentioned herein is withdrawn.
Claim Status
Claims 1-7 and 13-26 are pending. Claims 13 remains withdrawn as being directed to a non-elected invention. Claim 26 is new. Claims 1-7 and 14-26 are examined on the merits herein.
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 6-7 and 22-25 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Where applicant acts as his or her own lexicographer to specifically define a term of a claim contrary to its ordinary meaning, the written description must clearly redefine the claim term and set forth the uncommon definition so as to put one reasonably skilled in the art on notice that the applicant intended to so redefine that claim term. Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999). The term “wide-type” in claim 6 is used by the claim to apparently refer to a “wild type” bacteria, which is the common term used in the art for a natural bacteria type strain having no particular mutations or modifications. The specification describes that “Two types of P. gingivalis were used: a wild type and a mutant type (Akpg rgpA rgpB) lacking a protease” ([0127]). There is no definition or support for the term “wild-type” in the instant disclosure.
Although at first the term “wide-type” appears to be a typo for “wild-type”, it is noted that the Applicant’s arguments and remarks, on page 9 of the amendment filed 7/29/2025 also repeatedly use the term “wide-type”. Thus, it appears likely that this was an intentional recitation of the term and not a grammatical/typographical error. As the term is not known in the art, the term is indefinite because the specification does not clearly redefine the term. There is no manner for one to determine the metes and bounds of the claimed “wide-type bacteria” strain and thus the claim scope is indefinite.
Claims 7 and 22-25 depend directly or indirectly from the rejected claims and are, therefore, also rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, for the reasons set forth above.
Claim Interpretation
The term “wide-type” is being interpreted as discussed above, and for the purposes of the grounds of rejection presented herein, meaning the same as “wild type”, in reference to the bacteria that is applied to the tissue structure.
The following claim limitations are being interpreted according to the B.R.I. of the terms in view of the specification, as set forth in the prior action.
The term “cell structure” is defined in the instant specification ([0011]) as a “cell aggregate in which cells are three-dimensionally arranged through extracellular matrix components and which is artificially produced through culture”. The specification further states that “[h]ere a biological tissue includes sweat glands, lymph vessels, sebaceous glands, and the like and has a more complicated structure than the cell structure. For this reason, it is possible to easily distinguish the cell structure from a biological tissue”. Thus, under the broadest reasonable interpretation (B.R.I.) in light of the specification, the claimed “cell structure” is being interpreted as an artificially produced cell aggregate (i.e. cell model). One skilled in the art would recognize the markedly distinct characteristics when compared to a naturally obtained tissue (such as an ex-vivo tissue culture model).
The term "extracellular matrix component" is defined in the present specification as extracellular matrix molecule aggregates formed by a plurality of extracellular matrix molecules, and the extracellular matrix refers to a substance existing outside cells in an organism ([0020]).
The term "fragmented" has been interpreted herein according to the instant specification to mean an aggregate of extracellular matrix components that has been made smaller in size ([0021]). The fragmented components may be obtained, as an example only, the application of physical force (see [0022]-[0023]).
The limitation “wherein the expression of adhesion factors in the cell structure is promoted, as recited in claim 21 is herein interpreted under the B.R.I in light of the specification, to recite a functional limitation of an intrinsic property that occurs from the physiological activity of the cultured cells, in particular the epithelial cells which must have strong adhesion between cells to make a barrier (see [0128]-[0133] and table 2] of the specification). Thus, any prior art structure that describes the structural components including epithelial cells such as the Epi4 cells used in the instant invention will predictably have the inherent property of promoting expression of adhesion factors under similar conditions. See MPEP §§ 2112.01 and 2114.
Claim Rejections - 35 USC § 103
(Modified, as necessitated by Applicant’s amendments)
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-5 and 14-21 are rejected under 35 U.S.C. 103 as being unpatentable over “Toppan” (WO2018143286, of record), in view of Kim et al. ("Effects of collagen IV and laminin on the reconstruction of human oral mucosa." Journal of Biomedical Materials Research: An Official Journal of The Society for Biomaterials, The Japanese Society for Biomaterials, and The Australian Society for Biomaterials and the Korean Society for Biomaterials 58.1 (2001): 108-112, herein referred to as “Kim”).
Toppan, ’286, teaches three-dimensional tissue structures comprising at least a connective tissue structure (e.g. collagen) and an epithelial structure (e.g. layers of epithelial cells) (Abstract, Title). Toppan teaches that an epithelial structure is placed on the connective tissue structure, wherein the connective tissue structure comprises a fragmented extracellular matrix component (paragraphs [0040]-[0042] of the machine translation) and teaches using collagen-producing cells, comprising mesenchymal cells ([0014], which discloses “collagen-producing cells include mesenchymal cells”; see also [0042]-[0043]).
Toppan ’286 teaches that the three dimensional tissue structure further comprises epithelial cells and states that “cells constituting the three-dimensional tissue may further include one or more types of cells other than collagen-producing cells ([0026]). Examples of the other cells include, inter alia, “human gingival epithelial cells” ([0026], line 6; see also [0032] and [0043]). Toppan also teaches working examples (e.g. Example 10, [0076]-[0080]; Fig. 14) and methods for producing three-dimensional tissue structures ([0050]-[0051]), comprising contacting connective tissue structures, including contacting fragmented collagen ([0040-0042]) with mesenchymal cells, and adding epithelial cells.
Toppan explicitly describes, in Example 10, that a lower layer was prepared with fragmented collagen and human gingival fibroblasts (HGFs), that were “mixed and suspended” in DMEM media and cultured together ([0076]), thus teaching “at least a part of the fragmented extracellular matrix component between the first cells” as the fragmented collagen would be uniformly dispersed among the HGF cells (see [0035]). Following this, a second layer of human gingival epithelial cells (the Epi4 cell line) were seeded on top of the fibroblast and collagen-containing layer ([0077]).
Regarding claims 2 and 19, Toppan teaches that the mesenchymal cells include fibroblasts ([0014]), including human gingival fibroblasts ([0076]).
Regarding claims 3 and 15-18, Toppan teaches that the ECM component is fragmented collagen, such as fibrous collagen that maintains its triple helix structure ([0040]), that can be obtained by homogenizing fibrous collagen in an aqueous medium such as physiological saline (i.e. PBS)([0040]). Concerning the size of the fragmented collagen, Toppan teaches that “the average length of the fragmented collagen is preferably from 100nm to 200µm”, and that the average diameter is “more preferably 4µm to 30µm” ([0040], at end of paragraph).
Regarding claims 4 and 5, Toppan teaches a three-dimensional tissue using human skin-derived fibroblasts (NHDF) and human umbilical vein-derived vascular endothelial cells (HUVEC) mixed with fragmented collagen (forming the connective tissue layer) cultured with DMEM and vascular endothelial cell-dedicated medium ([0064]). Toppan states that this culture technique formed a three-dimensional tissue body including capillaries, which is a type of vascular network ([0064]). Thus, the connective tissue structure of Toppan includes those having a vascular network among the “first cells” or in other words, between the human skin-derived fibroblasts (NHDF) which are also mesenchymal cells (Toppan [0031]).
Regarding claim 14, which recites that the culture time of the “first cells” is 1 week to 2 week, Toppan teaches that “the culture time may be from 1 day to 2 weeks, or from 1 week to 2 weeks” ([0051]). In the particular embodiment described in Example 10, using HGF cells and human gingival epithelial cells, the cells were stated to be cultured for “7 days” or 1 week ([0078]). In another embodiment, in Example 3, Toppan teaches mixing fragmented collagen with aorta SMCs (e.g. aortic smooth muscle cells, a type of mesenchymal cells) and human umbilical vein-derived vascular endothelial cells (HUVEC) to produce a vascularized 3D tissue structure and culturing these cells for one week ([0064]).
Regarding claim 20, Toppan teaches an embodiment, Example 10, wherein the total amount of human gingival fibroblasts in a 3D tissue model is 1.0×10 6 cells ([0076]) and no other cells are described as being added to the connective tissue structure. Thus the fibroblasts would be 100% of the cells in the connective tissue structure and meet the instant limitation of “greater or equal to 30%”. Elsewhere ([0047]), Toppan teaches that the ratio of collagen-producing cells to other cells may be 99:1 (99%) to 9:1 (10%), 80:20 (80%) to 50:50 (50%), 20:80 (20%) to 50:50 (50%), or 10:90(10%) to 50:50(50%). Thus Toppan teaches various proportions of collagen-producing cells, i.e. fibroblasts, that overlap or fall within with the instantly claimed range (of 30% to 100%).
Regarding claim 21, the claimed limitation is being interpreted as reciting a functional property of the cultured cell line, and thus the expression of the adhesion factors is a functional limitation regarding an inherent property of the cell(s). Toppan teaches, in Example 10, producing a 3D tissue structure that includes a connective tissue structure from fragmented collagen and gingival fibroblast cells (as discussed above) and a layer of immortalized human gingival epithelial cells (the Epi4 cell line) were used on top ([0076]). Thus, the prior art teaches the Epi4 cell line being cultured under identical conditions as in the claimed cell structure and these cells would inherently produce or express the adhesion factors.
However, Toppan does not teach that a surface of the connective tissue structure is coated with a layer of collagen IV, as recited in the amended claim 1.
Kim et al. is a research article describing the effects of basement membrane proteins on the reconstruction of an oral mucosa equivalent, and teaches that an oral mucosa substitute was cultured on (1) type I collagen gels, (2) type IV collagen-coated type I collagen gels, (3) laminin-coated type I collagen gels, and (4) type I collagen gels containing both type IV collagen and laminin (Abstract). Kim teaches that type IV collagen and laminin are important in the process of differentiation in mucosal keratinocytes (Abstract). Further, Kim teaches coating a type I collagen gel with both Col IV and laminin results in the best model for (pg. 110, Figure 1 legend: “Normal oral mucosa and reconstructed mucosa. Among the four models, the [Coll IV + LAM] mucosa was most similar to normal mucosa in terms of the shape of the basal cells and the alignment along the basement membrane areas … (e) reconstructed mucosa on type IV collagen plus laminin-coated type I collagen gel.”). Kim teaches that mucosal epithelial cells are grown on the oral mucosa model, including on the layer comprising type IV collagen (see “Reconstruction of Oral Mucosa” on page 109 and Fig. 1).
Thus, Kim et al. teaches a cell culture model that has a connective tissue structure comprising an analogous extracellular matrix component (the type I collagen gel) which is coated with a layer comprising at least collagen IV, and that the use of at least collagen IV (preferably also with laminin) results in an improved tissue culture model.
To one of ordinary skill in the art, before the effective filing date of the instant invention, it would have been prima facie obvious to modify the three-dimensional tissue structure taught in Toppan, comprising an epithelial structure on a connective tissue structure which comprises fragmented collagen and mesenchymal cells such as human gingival fibroblasts (HGFs), wherein a surface of the connective tissue structure has a layer of collagen IV, as taught in Kim et al. for the predictable benefit of producing an improved oral mucosa cell model.
One would have been motivated to modify the model of Toppan by incorporating the collagen type IV coating taught in Kim because Kim teaches that the inclusion of collagen type IV, in combination with laminin in particular, results in a cell culture model that more closely models the cells in normal oral mucosa tissue. In other words, the provision of collagen type IV has previously been appreciated to improve oral mucosa tissue models including oral epithelial cells, and thus the application of this improvement to the analogous model taught in Toppan would be prima facie obvious. See MPEP § 2143, rationale C, which describes that the use of known technique to improve similar devices (methods, or products) in the same way is an obvious reason to combine the teachings of prior art, when the result of the combination would be predictable. In this case, the improvement of the characteristics of the epithelial cells, such as the improved differentiation of keratinocytes is specifically taught in Kim, would be predictable to one of ordinary skill in the art.
Regarding claims 2-5 and 15-19, these additional limitations are either explicitly taught in Toppan (such as providing of fibroblasts and vascular endothelial cells, see the human skin-derived fibroblasts (NHDF) and human umbilical vein-derived vascular endothelial cells (HUVEC) mixed with fragmented collagen that are used therein), or the additional elements recite functional properties arising from the selection and providing of these cell types (e.g. the production of a vascular network between the first cells/ the mesenchymal cells). Thus the selection and providing of these particular conditions of the cell structure (as recited in claims 2-5 and 15-19) would have been obvious choices and/or obvious functional properties of the prior art devices, in view of the cited combination of art.
Regarding claim 20, as discussed above, Toppan teaches various proportions of collagen-producing cells, i.e. fibroblasts, that overlap or fall within with the instantly claimed range (of 30% to 100%) and the selection and providing of the recited cell numbers would be a matter of judicious selection and routine optimization to one of ordinary skill in the art.
In regards to claim 21, the claimed composition comprising fragmented collagen, gingival fibroblast cells and immortalized human gingival epithelial cells (Epi4 cells), and the intrinsic expression of adhesion factors or proteins that promote adhesion by the cell lines, would have been rendered obvious by the cell structure of Toppan, modified according to Kim.
Thus, the referenced prior art composition is likely to inherently possess the same characteristics of the claimed composition, particularly in view of the similar characteristics which they have been shown to share and by the functions of the component materials (e.g. the two cell lines and the fragmented collagen) inherently present in each and which functions are inclusive of those appreciated in the instant disclosure as being present (see MPEP 2112.02 at Ex parte Novitski, in reference to reference-silent functioning of biological materials providing anticipation of the functions based upon the material itself, noting the reference of “Dart” therein did not appreciate the claimed function but still anticipated the function based on the inherent function of the material, and that the Applicant’s disclosure appreciating the function upon usage thereof as further evidence of the presence of the function, e.g. Table 2 of the instant disclosure).
Please note, since the Office does not have the facilities for examining and comparing Applicants’ composition with the composition of the prior art, the burden is on applicant to show a novel or unobvious difference between the claimed product and the product of the prior art. See In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977) and In re Fitzgerald, 619 F.2d 67, 205 USPQ 594 (CCPA 1980), and “as a practical matter, the Patent Office is not equipped to manufacture products by the myriad of processes put before it and then obtain prior art products and make physical comparisons therewith.” In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972).
From the teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention, wherein a layer of Type IV collagen is incorporated on an extracellular matrix, which is successfully demonstrated in Kim. The combination of Type IV collagen with the fragmented extracellular matrix based model of Toppan would have a predictable expectation of improved performance, and both references pertain to oral mucosa models. Thus, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art, as evidenced by the references, especially in the absence of evidence to the contrary.
Claims 1-7 and 14-23 are rejected under 35 U.S.C. 103 as being unpatentable over “Toppan” (WO2018143286, of record) and Kim et al. ("Effects of collagen IV and laminin on the reconstruction of human oral mucosa." (2001): 108-112), as applied to claims 1-5 and 14-21 above, and further in view of Pinnock et al. ("Characterisation and optimisation of organotypic oral mucosal models to study Porphyromonas gingivalis invasion." Microbes and infection 16.4 (2014): 310-319, on IDS filed 6/21/2023, of record) (to include the rejections of claims 6-7 and 22-23).
The combination of Toppan in view of Kim makes obvious a three-dimensional tissue structure comprising a layer of Type IV collagen, as explained above.
The relevant teachings of Toppan and Kim include all those set forth above.
Toppan specifically teaches a 3D tissue model using human skin-derived fibroblasts (NHDF) and human umbilical vein-derived vascular endothelial cells (HUVEC) mixed with fragmented collagen (forming the connective tissue layer) cultured with DMEM and vascular endothelial cell-dedicated medium ([0064]). Toppan states that this culture technique formed a three-dimensional tissue body including capillaries, a type of vascular network ([0064]).
Toppan suggests that the three-dimensional tissue structures having gingival fibroblasts may be useful for in vitro analysis of periodontitis ([0099]).
However, Toppan does not teach a bacteria-containing tissue model comprising the cell structure according to claim 1 and bacteria in contact with the epithelial structure of the cell structure, as recited in claim 6 and the dependent claims 7 and 22-25.
Pinnock et al. teaches the use of three-dimensional, organotypic mucosal models (OMM), composed of collagen-embedded fibroblasts overlain with multilayers of oral epithelial cells, to analyze infection of oral epithelial cells by Porphyromonas gingivalis (Abstract). Pinnock teaches that P. gingivalis is a Gram-negative, pathogen that significantly contributes to periodontitis, i.e. a periodontal disease bacteria (Introduction, pg. 310, first paragraph). The tissue model in Pinnock is made using type I collagen isolated from rat tails and treated with an acidic method to dissolve the collagen (pg. 311, right col, section 2.4). Human primary buccal fibroblasts were then suspended in a solution containing the disassociated collagen to make a solid model, and then keratinocytes, i.e. epithelial cells were adhered to the model. Pinnock et al. states that “OMMs used in this study displayed a well-organised architecture consisting of a multi-layered epithelium and a fibroblast-populated connective tissue layer” (pg. 312, right col, section 3.1 and see Fig. 1). Pinnock teaches that the oral tissue models were formed, P. gingivalis cells were contacted with the epithelium and invasion of the models was monitored over time (pg. 312, right col, section 3.1 - pg. 313, right col, 2nd para; Fig. 2; Fig. 3). Pinnock suggests that three-dimensional tissue models are more representative of oral tissues and that the 3D models are a more relevant in vitro model of the cellular microenvironment in vivo, as compared to previous two-dimensional models (pg. 318, last paragraph).
Pinnock teaches that the P. gingivalis cells may include wild-type (i.e. unmodified) cells (see section 2.2 Bacterial strains and culture conditions: “P. gingivalis strains NCTC 11834 (National Collection of Type Cultures), which is a reference-type strains, broadly wild-type).
To one of ordinary skill in the art, before the effective filing date of the instant invention, it would have been prima facie obvious to combine the three-dimensional cell structure of Toppan, modified according to the teachings of Kim, by incorporating a culture of bacterial cells, particularly P. gingivalis, for the predictable benefit of improved modeling of periodontal disease as taught in Pinnock and also suggested in Toppan.
One of ordinary skill would have been motivated by the suggestion of Toppan and the explicit teachings of Pinnock to use the model of oral epithelium tissue taught in Toppan and Kim for modeling periodontal disease because Pinnock teaches that multi-cellular, multi-layered tissue models are better than basic two-dimensional cultures for studying P. gingivalis infection.
MPEP § 2143(I), rationale C states that the use of known technique to improve similar devices in the same way is obvious, when the results of applying the “improvement” technique would have been predictable to one of ordinary skill in the art. In this case, the cell culture model of Toppan can be considered a “base” device, ready for improvement, e.g. the device has not been contacted with bacteria to model periodontal disease as in the claimed invention. Pinnock teaches a distinct 3D oral mucosal model (Pinnock does not teach using fragmented collagen) that has been exposed to P. gingivalis in order to study periodontal disease, thus a “comparable” device or technique to the claimed invention. Therefore, one of ordinary skill in the art would have been capable of applying periodontal disease bacteria, such as P. gingivalis to the device taught in Toppan to arrive at the instant invention.
Toppan and Piddock are both drawn to generating three-dimensional, multi-layered tissue models, and both discuss the construction of oral mucosal, i.e. oral epithelium tissue models.
Regarding claim 22, Toppan teaches using gingival fibroblasts and Piddock teaches using primary buccal fibroblasts. Thus using fibroblasts as the mesenchymal cells would have been obvious in view of the combination of teachings in the art.
Regarding claim 23, Toppan teaches using fragmented collagen, as described previously.
From the teachings of Pinnock, Toppan, and Kim, and from assessing the level of ordinary skill in the art, it is apparent that one of ordinary skill would have had a reasonable expectation of success in producing the claimed invention as each are in related arts of modeling oral mucosa and/or oral disease, and the use of P. gingivalis in 3D tissue models is known (see Pinnock). Therefore, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art prior to the instant invention, as evidenced by the cited references, especially in the absence of evidence to the contrary.
Claims 1-7 and 14-25 are rejected under 35 U.S.C. 103 as being unpatentable over “Toppan” (WO2018143286), Kim et al. ("Effects of collagen IV and laminin on the reconstruction of human oral mucosa." (2001): 108-112), and Pinnock et al. (Microbes and infection, 2014, on IDS filed 6/21/2023) as applied to claims 1-7 and 14-23 above, and further in view of Heller et al. ("Tissue engineered pre-vascularized buccal mucosa equivalents utilizing a primary triculture of epithelial cells, endothelial cells and fibroblasts." Biomaterials 77 (2016): 207-215, on IDS filed 6/21/23) (to include rejections of claims 24 and 25).
The combination of Toppan, Kim, and Pinnock make obvious the cell structure and bacteria-containing tissue model of claims 1 and 6, for all of the reasons described above.
The teachings of Toppan, Kim, and Pinnock are as set forth previously.
In regards to claims 24 and 25, interpreted as described above to recite that the connective tissue must contain endothelial cells and there exists a vascular network between the mesenchymal cells (i.e. the fibroblast cells), Toppan teaches an embodiment in which the connective tissue layer may further include HUVEC cells so that capillary network is formed between the mesenchymal cells.
However, the combination of Toppan, Kim, and Pinnock does not teach explicitly that oral (gingival) epithelial cells are used with the vascular-producing endothelial cells and gingival fibroblasts, such that a model for applying periodontal bacteria is produced.
Heller teaches generating a vascularized buccal mucosa model using a tri-culture of primary buccal epithelial cells, fibroblasts and microvascular endothelial cells (Abstract). Heller teaches that co-culture of buccal mucosa fibroblasts and human dermal microvascular endothelial cells (HDMECs) forms a capillary-like vascular structure (pgs. 208-209, sections 2.2 and 2.3; Figs. 1 and 2). Heller teaches that this pre-formed capillary-like structures mimics in vivo buccal mucosa (section 5. Conclusions, pg. 214-215).
To one of ordinary skill in the art, before the effective filing date of the claimed invention, it would have been obvious to further modify the bacteria-containing tissue model of Toppan, modified by Kim and Pinnock, so that the connective tissue structure having fragmented collagen and fibroblasts further includes vascular endothelial cells as taught in Heller, and the connective structure is seeded with oral epithelial cells, to yield a vascularized buccal (oral) mucosa model for applying periodontal-disease causing bacteria as taught in Pinnock.
One would have been motivated by the teachings of Heller to add vascular forming cells such as HDMECs to the fragmented-collagen and fibroblast-containing scaffold taught in Toppan, as the presence of blood vessels would more accurately model the human oral epithelial tissue (i.e. for studying gum disease) as taught in Heller. It would have been within the ordinary level of skill in the art to apply an periodontal disease-causing bacteria, as taught in Pinnock, for the expected benefit of better modeling human periodontitis using the vascularized tissue.
From the teachings of Toppan, Kim, Pinnock, and Heller concerning oral tissue models, especially in view of the data in Heller that vascular endothelial cells form vascularized networks when mixed with fibroblasts in the presence of collagen, it is apparent that one of ordinary skill would have had a reasonable expectation of success in producing the claimed invention.
Thus, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art prior to the instant invention, as evidenced by the cited references, especially in the absence of evidence to the contrary.
Claims 26 (newly presented) is rejected under 35 U.S.C. 103 as being unpatentable over “Toppan” (WO2018143286) and Kim et al. ("Effects of collagen IV and laminin on the reconstruction of human oral mucosa." (2001): 108-112) as applied to claim 1 above, and further in view of Davidenko et al. ("Control of crosslinking for tailoring collagen-based scaffolds stability and mechanics." Acta biomaterialia 25 (2015): 131-142.)
The combination of Toppan in view of Kim makes obvious a three-dimensional tissue structure comprising a layer of Type IV collagen, as explained above.
The relevant teachings of Toppan and Kim include all those set forth above.
Toppan specifically teaches a 3D tissue model using human skin-derived fibroblasts (NHDF) and human umbilical vein-derived vascular endothelial cells (HUVEC) mixed with fragmented collagen (forming the connective tissue layer) cultured with DMEM and vascular endothelial cell-dedicated medium ([0064]).
However, Toppan does not teach explicitly that a part of the fragmented extracellular matrix component is crosslinked between molecules constituting the extracellular matrix component and a degree of crosslinking of the fragmented extracellular matrix component is greater than or equal to 1% and less than or equal to 30%.
Davidenko et al. pertains to optimization of tissue engineering methods for cross-linking collagen-based scaffolds (Title, Abstract). Davidenko teaches that scaffolds were cross-linked using a carbodiimide treatment, to establish the effect of the variations in crosslinking conditions (down to very low concentrations) on the morphology, swelling, degradation and mechanical properties of the scaffolds (Abstract). Davidenko states that “controlling the degree of cross-linking, and hence retaining native scaffold chemistry, offers a major step forward in the biological performance of collagen- and gelatin-based tissue engineering scaffolds”.
Specifically, Davidenko teaches using type I microfibrillar collagens-based scaffolds (see section 2.1. “Materials”) and that the protein scaffolds were chemically cross-linked using a water-soluble carbodiimide (EDC) in presence of NHS at different concentration (see section 2.3 “Scaffold crosslinking”). Davidenko teaches determining the degree of crosslinking (see Table 2), with testing of a range between 0 and up to 81% of crosslinking. Further characterization of the scaffolds indicates that a lower concentration of between ~8% to 26% of crosslinking (see Table 2 for the degree of crosslinking with 1 and 10% EDC concentrations for Col(S), and see the results of Fig. 9) had the optimal results regarding cell attachment and biocompatibility (page 140, left col: “This data provides a maximal degree of side chain consumption that is compatible with bioactivity. In the case of Col(S) compositions this equates to ~26% of amine crosslinking”, and see pg. 139 left col: “Together these date indicate that by utilising lower EDC/NHS crosslinking conditions it is possible to preserve native-like integrin 21 mediated cell interactions with collagen-based materials”).
Therefore, to one of ordinary skill in the art, it would have been prima facie obvious to modify the three-dimensional cell structure of Toppan, modified according to the teachings of Kim, by crosslinking the fragmented collagen-containing scaffold material of Toppan according to the teachings of Davidenko, such that an optimal crosslinking degree which falls between the instantly claimed range of 1-30% is achieved,
One would have been motivated to crosslink the scaffold material (the fragmented collagen or extracellular matrix components) according to the teachings of Toppan and Davidenko, because Davidenko teaches that controlling the degree of cross-linking, and hence retaining native scaffold chemistry, improves the biological performance of collagen-based tissue engineering scaffolds. Davidenko also teaches further that a degree of crosslinking of 26% had optimal performance when tested according to the conditions therein, and resulted in the best results for biocompatibility (e.g. cell attachment, cell morphology and other features). Therefore, one of ordinary skill would have been aware of the importance of controlling the degree of crosslinking, and would have been able to arrive at the instantly claimed combination.
Indeed, the Davidenko reference is cited in the instant disclosure, which states “[0035] In a case where an amino group in an extracellular matrix component is used for cross-linking, the degree of cross-linking can be quantitatively determined based on a TNBS (2,4,6-trinitrobenzene sulfonic acid) method disclosed in Acta Biomaterialia, 2015, Vol. 25, pp. 131-142 or the like. The degree of cross-linking obtained through the TNBS method may be within the above-described ranges”. Thus, it is evident that crosslinking of collagen0based scaffolds (comprising extracellular matrix material) and methods of measuring the degree of crosslinking is known to the art, as indicated by the Applicant’s own disclosure herein.
From the teachings of the Davidenko reference, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention, particularly in that crosslinking of collagen based scaffolds is well known to the art, and Davidenko teaches optimizing the degree of crosslinking to improve cell culture.
Therefore, the invention of claim 26 as a whole would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date, as evidenced by the references, especially in the absence of evidence to the contrary.
Response to Arguments
Applicant's arguments regarding the previous cited art documents, filed 7/29/2025, on pages 8-10 of the remarks, have been fully considered but they are not persuasive in light of the amendments and the additional considerations described above.
Applicant’s arguments with respect to the rejections of the claims as being obvious have been considered but are moot because the new grounds of rejection do not rely on the reference (and reference combinations) applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Additional art has been cited to address the newly added limitations.
Applicant argues that the prior art references do not teach each and every limitation of the amended claims, particularly that the cited references do not teach a layer of type IV collagen applied to at least one surface of an connective tissue structure. However, the feature upon which the Applicant argues was not recited in the previous claim set. Upon further search and consideration, the reference Kim et al. (2001, cited above) is now cited for teachings regarding the application of type IV collagen in a three-dimensional oral mucosa model, wherein the application of type IV collagen results in an improved tissue model.
Generally, in response to applicant's arguments, it is also noted that the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). The examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007).
Further, Applicant’s arguments pertaining to the use of a “wide-type” (e.g. a wild-type strain as best interpreted according to the B.R.I.) P. gingivalis strain are not persuasive, as the use of wild-type strain is clearly taught in Pinnock 2014, and thus it is predictable to one of ordinary skill that a wild-type strain of P. gingivalis, a known oral pathogen, is capable of infiltrating the tissue model, vascular network, and epithelial cells.
The Declaration under 37 CFR 1.132 filed 7/29/2025 has been fully considered, however, is insufficient to overcome the rejections of the claims based upon the findings of obviousness under 35 U.S.C. § 103, as set forth in the last Office action, because the facts presented are not germane to the rejections at issue over the instant claims, and the showing is not commensurate in scope with the rejected claims. See also MPEP § 716.
The pending claim 1 recites a cell structure comprising: a connective tissue structure; and an epithelial structure placed on the connective tissue structure, wherein the connective tissue structure comprises a fragmented extracellular matrix component and first cells comprising mesenchymal cells, wherein at least a part of the fragmented extracellular matrix component is placed between the first cells, wherein the epithelial structure comprises epithelial cells, and wherein a surface of the connective tissue structure is coated with a layer of collagen IV..
The Applicant sets forth that the declaration contains a showing that “there is significant benefit associated with the presence of a layer of type IV collagen. Specifically, as shown in Fig. 1 and Table I in the attached 1.132 Declaration, the number of cells increased significantly when there is presence of a layer of type IV collagen compared to that when there is no type IV collagen at all times after plating. Thus, these results demonstrate that the presence of a layer of type IV collagen promotes significantly cell adhesion and proliferation.”.
However, examination of the experimental conditions reveals that the data presented in the declaration of 7/29/2025 was not obtained under conditions commensurate with the claimed structure. The materials and methods, on page 3 of the declaration, indicates that cover glasses were coated with or without human collagen IV solution, and then the epi4 cells were plated on the cover glass, with or without the collagen IV coating. The resulting data is said to indicate the benefits of collagen IV on cell adhesion in the claimed cell model.
However, it is noted that the claimed cell model is clearly distinct from the experimental conditions. The claimed cell structure requires a connective tissue structure, wherein the connective tissue structure comprises a fragmented extracellular matrix component and first cells comprising mesenchymal cells. The collagen solution in the experiments of the declaration was only applied to a glass surface, and in addition the control cells were merely plated on the glass surface (without the collagen). These conditions are thus very different from the conditions of the claimed subject matter, wherein a tissue structure having fragmented extracellular matrix components and mesenchymal cells is required. Thus, the showing of improved cell adhesion when adding collagen type IV to a glass surface is not considered relevant to the instantly claimed issue, wherein cells (with or without collagen) are added to a three-dimensional tissue structure (i.e. tissue model). The prior art cited in the previous rejection, sets forth the general level of knowledge in the art, and specifically teaches using fragmented extracellular matrix components with mesenchymal cells (see Toppan et al., as set forth above). Further, the addition of the type IV collagen layer has been found obvious, for the reasons set forth above, as such collagen IV coatings have been employed previously in the art (Kim et al., of record).
Thus, the declaration filed 7/29/2025 has been fully considered but is deemed insufficient to overcome the present rejection of the claims as being obvious under 35 U.S.C. § 103.
Double Patenting
(modified, as necessitated by amendments)
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1-3, 6-7, 14-19, and 22-23 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-2, 5-6, and 18 of U.S. Patent No. 11,179,495 in view of Pinnock et al. (Microbes and infection 16.4 (2014), of record) and Kim et al. ("Effects of collagen IV and laminin on the reconstruction of human oral mucosa." Journal of Biomedical Materials Research: An Official Journal of The Society for Biomaterials, The Japanese Society for Biomaterials, and The Australian Society for Biomaterials and the Korean Society for Biomaterials 58.1 (2001): 108-112).
The reference (‘495) claim 2 recites a three-dimensional tissue, comprising cells and collagen, wherein the collagen includes: a plurality of fragmented collagen pieces fragmented from each other in fragmented form derived from exogenous collagen, wherein at least a portion of the cells is adhered to the collagen, the plurality of fragmented collagen pieces are uniformly distributed among the cells three-dimensionally throughout the three-dimensional tissue, the cells and the plurality of fragmented collagen pieces in the fragmented form are in contact, respectively (as recited in the reference claim 1), and wherein the cells comprise a collagen-producing cell. The reference claim 5 recites that the cells may comprise one or more types of cells selected from vascular endothelial cells, cancer cells, cardiomyocytes, smooth muscle cells, and epithelial cells.
Reference claim 1 also recites that an average length of the fragmented collagen pieces is from 100nm to 200µm.
The reference claim 6 recites a three-dimensional cell structure in which the average diameter of the fragmented collagen pieces is from 50nm to 30µm.
When considering the claimed scope of a “collagen-producing cell” in claim 2 of the ’495 patent, the disclosure defines a “collagen-producing cell” as a cell that secretes collagen such as fibrillar collagen. Examples of the collagen-producing cell include mesenchymal cells such as fibroblasts (Col 5, lines 4-10). Further, the specification defines “fragmented collagen” as collagen obtained by fragmenting collagen, such as fibrillar collagen, and having a triple helix structure. (Col 9, lines 59-61). MPEP § 8 B.1. states that “[t]he specification can be used as a dictionary to learn the meaning of a term in the claim. Toro Co. v. White Consol. Indus., Inc., 199 F.3d 1295, 1299, 53 USPQ2d 1065, 1067 (Fed. Cir. 1999)”. Thus, in order to ascertain the scope of the claim terms, these special definitions from the specification have been considered. Therefore, the scope of the reference claim 2 is deemed to include mesenchymal cells such as fibroblasts.
However, the reference claims do not disclose that:
the epithelial cells are placed on top of the layer of fragmented collagen and mesenchymal (“collagen-producing cells”),
that the cells include human gingival epithelial cells, nor
that bacteria are in contact with the epithelial structure of the cell structure.
a surface of the connective tissue structure is coated with a layer of collagen IV.
The t