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 .
Status of the Claims/Application
Claim 1 is currently amended. Claim 21 is new. Claims 1-21 are pending and are under examination herein.
Priority
The instant application filed on 05/10/2022, claims priority to the US Provisional application 63/186470, filed on 05/10/2021.
Maintain/New Rejections
Rejections Under 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 1-21 are rejected under 35 U.S.C. 103 as being unpatentable over US 2017/0362266 A1, and further in view of, Li et al. Transplantation of Human Mesenchymal Stem-Cell-Derived Exosomes Immobilized in an Adhesive Hydrogel for Effective Treatment of Spinal Cord Injury. Nano Lett. 2020 Jun 10;20(6):4298-4305, Madl et al. Bioorthogonal Strategies for Engineering Extracellular Matrices. Adv Funct Mater. 2018 Mar 14;28(11) and Wang et al. Integrating Protein Engineering and Bioorthogonal Click Conjugation for Extracellular Vesicle Modulation and Intracellular Delivery. PLoS One. 2015 Nov 3;10(11):e0141860, herein further to referred to as Ott, Li Madl and Wang respectively.
Regarding claims 1-21, Ott teaches a method for preparing a biological prosthetic mesh wherein a functionalized decellularized scaffold (ECM) is reacted with a biologically active molecule functionalized with a reactive group complementary to the reactive group of the functionalized ECM (Ott para 0032). Ott teaches that ECM that can be functionalized with azide ligands such as Ac4GalNAz or with a chemical group that is reactive in a biorthogonal reaction (Ott Abstract). Ott teaches that alkyne biomolecules can be immobilized in azide functionalized ECM in via a bioorthogonal reaction (Ott Fig. 1 A-e). Ott further teaches that the chemical group used to functionalize the ECM can be an azide, an alkyne, a nitrone, an isocyanide, a cyclopropene or and tetrazine (Ott para 0019) whereby the alkyne can be a cyclooctene such as DBCO, DIFBO, DIFO (Ott para 0035 - 0036). Ott further teaches that the reaction between the azide ligand and the azide complementary reagent can be a click reaction such as azide-to-cyclooctyne click reaction (Ott para 0130). Ott further teaches that the biorthogonal reaction can also be a Staudinger reaction between an azide and a phosphine (Ott para 0122 and 0156). Ott further teaches that the tissue or organ that can be used for applying the invention includes carotid artery, lung, heart, liver, kidney and skin (Ott para 0018). Regarding the claims where the immobilized extracellular vesicle is used in an application for tissue regeneration, post-ischemic injury repair etc., Ott also teaches that the functionalization of ECM through immobilization of bioactive molecules is promising method to facilitate organ/tissue regeneration (Ott pg. 1 para 0005) and Ott further teaches that the method can be applied to immobilize anti-TNF-alpha antibody (TNF-alpha is a main cause of ischemia) onto the donor organ during its cold preservation, thus neutralizing TNF-alpha produced by ischemia/perfusion and thereby advantageously protecting the donor lung graft and improve its transplantation outcomes (Ott pg. 6 para 0119)
While Ott primarily teaches that ECM can be functionalized with azide tags and then conjugating the functionalized ECM to a bioactive molecule comprising an azide complementary reagent, it also teaches that ECMs can be functionalized with either an azide ligand or an azide complementary reagent. Ott did not specifically teach about immobilizing EV in ECMs that is used for tissue regeneration, post-ischemic injury repair etc.
Regarding the limitation where the EVs are isolated from mesenchymal stem cells (MSC) and are biologically active, Li teaches of EVs that were isolated from mesenchymal stem cells (EV-MSC) (Li pg. 4299 para 4 ln 1-4) that expressed tetraspanins CD63 and CD9 makers (indication of biological activity) (Li pg. 4299-4300 para 4 ln 1-13) wherein the EVs were immobilized within hydrogel (ECM) and then used for the treatment of spinal cord injury (Li Abstract), CNS disease and tissue trauma (Li pg. 4299 para 2 ln 9-16). Li teaches that because of the paracrine activities that exosomes (EV) inherit form MSCs, they are potentially effective tools for delivering therapy. Li further teaches that Hyaluronic acid is a linear polysaccharide in natural ECM but lack adhesive cues for cells and cell-derived biomembranes making it difficult for them to deliver local therapeutic effects over a desired time frame. Li further teaches that the surface of EVs can be modified to enhance its adhesiveness to ECM (Li. Pg. 4299 col 1 para 1) thereby prolonging it activity at the desired site where therapeutic effects are desired.
Regarding the type of reaction chemistry for attaching a cyclooctyne or phosphine reagent to the ECM as recited in claim 14, Madl teaches different biorthogonal crosslinking strategies allowing for gentle and efficient encapsulation of cells in various hydrogels materials in other to alter matrix mechanical properties and biochemistry on demand (Madl Abstract). Madl further teaches that azide, cyclooctenes such as BCN or triarylphosphine can be used to functionalize ECM for biorthogonal crosslinking (Madl Fig. 4 D). Madl also teaches that hydrogel crosslinking and functionalization must be compatible with living cells and that 3D cell encapsulation utilizes covalent crosslinking. Madl teaches that this can be achieved by using chemical crosslinkers that react with amines and sulfhydryls that can react with these same functional groups present in cell surface proteins (Madl pg. 1 col 2 ln 1-28). Madl further teaches different pairs of biorthogonal reaction types that can be potentially used to functionalize hydrogel precursors for engineering ECMs. And that the ideal gelation reaction for applications such as cell encapsulation should be completed within minutes to ensure homogenous cell distribution within the ECM. Madl list other parameter that are essential for selecting the type of biorthogonal pair (Madl pg. 2 col. 2 para 2 – pg. 3 col 1-col 2, Fig. 2 and Tab. 1).
Regarding the recitations in claims 9 - 11 whereby the functionalization of the EV with the azide ligand is by attaching the azide ligand through metabolic glycan or amino acid engineering that targets the EV’s native pathway for sialic acid glycosylation in a cell culture by introducing the azide probe into the culture. Wang teaches the functionalization and conjugation of EV for intracellular delivery. Wang teaches a strategy that combines metabolic labeling of newly synthesized proteins or glycan/glycoproteins of exosomes-secreting cells with active azides and biorthogonal click conjugation to modify and functionalize exosomes (Wang Abstract). Wang teaches that L-azidohomoalanine (AHA), an azide-bearing amino acid analogue of methionine introduced unnatural azides into exosomes thereby providing additional chemically active sites for exosome bioconjugation through azide-involved biorthogonal reactions. Wang teaches that the metabolization of azide-bearing saccharides during the glycan biosynthesis process could simultaneously integrate the saccharides into exosomes and that the co-cultured exosome secreting cells with tetraacetylated N-azidoacetyl-D-mannosamine (ManNAz), an azido-sugar that can be metabolized into sialic acid, and obtained ManNAz-integrated exosomes in a manner similar to that of AHA-metabolized exosomes. Wang further teaches that the incorporation of AHA or ManNAz into exosome enables the functionalization of exosomes via a broad range of azide-involved reactions such as azide-phosphine ligation and azide-alkyne cycloaddition click chemistry (Wang pg. 3-4 para 3). Wang further teaches the metabolic engineering strategy can be applied to other substrates that are capable of integrating into multivesicular bodies (Wang pg. 10 para 2). Wang also teaches that a cargo such as a drug can be attached to the exosome (Wang Fig. 1) for drug delivery purposes (Wang pg. 6 para 3).
Therefore, it would have been obvious before the effective filing date for s skilled artisan to modify the teachings of Ott in view of Li Madl and Wang with a reasonable high degree of predictable success so as to immobilize a functionalized EV into a functionalized ECM to obtain a bioactive material that can be used for tissue regeneration, would healing for different tissues or organs. As indicated by Ott, ECMs can me functionalized with either an azide or an azide complementary reagent using the methods described by Madl in which ECM where functionalize by an azide and azide complementary reagent in other to achieve matrix crosslinking. Madl shows that ECM can be functionalized with an azide complementary reagent by several types of reactions including amine reactive reactions. Furthermore, Wang also illustrates that EV can be functionalized with azides tags and in other to deliver the functionalized EV intracellularly. Also, that a cargo such as a drug can be attached to the cargo for drug delivery purposes. Therefore, a skilled artisan would have been able to modify the teachings of Ott by functionalizing the ECM with an azide complementary reagent such as BCN or DBCO using the chemical reaction methods as described by Madl, and functionalizing the bioactive molecule of Ott, such as EV (exosome) with an azide tag/ligand in a similar manner as described by Wang and then applying an azide-cyclooctyne or Staudinger reaction in order to achieve an immobilized EV in ECM for the use to deliver site specific therapeutic benefit and extend the duration of EV as suggested by Li’s immobilized EV in hydrogel. Although Li used a different mechanism to achieve the immobilized EV, a skilled artisan would have been motivated to immobilized the EV in ECM by applying a biorthogonal pair reaction as this method is common method in the art to engineer ECM or to encapsulate cells in ECM (EV members and cell membranes have similar glycan/glycoprotein structure that can be employed via metabolic engineering techniques) so as to obtain the immobilized EV in other to improve the therapeutic effectiveness of the biomaterial used for wound healing tissue regeneration etc. by employing the methods of Ott in view of Li, Madl and Wang to attach a cargo to the EV that would deliver an improved therapeutic effect as well as a longer duration to the EV at the target site.
Response to Arguments
Applicant's arguments filed 12/02/2025 have been fully considered but they are not persuasive.
The rejections has been simplified and therefore, Rayamajhi, Laughin and Klymiuk are no longer used as prior art reference for the rejections.
In response to applicant's argument that “Ott teaches functionalization of the extracellular matrix material, it is not functionalized with azide-complimentary reagent but is rather functionalized with azide, the reverse of what is described in amended claim 1” (Remarks pg. 6 para 4). As indicated in the rejection above, Ott teaches that the ECM can be functionalized with either an azide complementary reagent or an azide ligand. Ott further teaches that the chemical group used to functionalize the ECM can be an azide, an alkyne, a nitrone, an isocyanide, a cyclopropene or and tetrazine (Ott para 0019) whereby the alkyne can be a cyclooctene such as DBCO, DIFBO, DIFO (Ott para 0035 - 0036).Furthermore, the claims are not drawn to an improved biochemical or mechanical properties as a result of functionalizing the ECM according to the method as claimed and therefore were interpreted and analysis as such.
Applicant also argues that Rayamajhi and Wang teaches functionalizing an EV with a cargo of interest for delivery and not for immobilizing it in an ECM and that there is no suggestion or motivation to immobilize EV in an ECM in these references (Remarks pg. 7 para 1). Rayamajhi has been removed as prior art so as to simplify the rejection. Regarding Wang, he teaches a method to functionalize EV, and therefore a skilled artisan looking to functionalize and immobilize an EV in an ECM in a manner that is different from Li’s and to improve the adhesion of EV in the ECM would have followed the suggestions of Wang to expand on the functions that can be introduced to into the EV as a result of attaching the azide ligand through metabolic glycan engineering (Wang Abstract).
Applicant further argues that Li uses a different mechanism to immobilized the EV in ECM (Remarks pg. 7 para 2). Although Li uses a different mechanism, Li teaches that the surface of EVs can be modified to enhance its adhesiveness to ECM (Li. Pg. 4299 col 1 para 1) thereby prolonging it activity at the desired site where therapeutic effects are desired. Therefore, a skilled artisan seeking to improve the therapeutic effects of an EV would have been motivated to follow Li’s suggestion to immobilize it in the ECM regardless of the method or mechanism to which the immobilization is accomplished.
Finally applicant argues that the problem addressed by Ott’s invention is different from the own the applicant seeks to address (Remarks pg. 8 para 2). Ott seeks to functionalize an ECM to thereby providing a prosthetic mesh and mammalian organ/tissues used in transplantation and tissue regeneration (Ott Abstract) which is in the same art as the method or biomaterial claimed in the claims. Furthermore, Ott is drawn to using similar methods as claimed for functionalizing ECM or bioactive materials. Furthermore, the applicant argues that previous methods for functionalizing the ECM using this methods could cause unwanted biochemical and mechanical properties. The claims are not drawn to an improved biochemical or mechanical properties as a result of functionalizing the ECM according to the methods claimed and therefore were interpreted and analysis as such.
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). As indicated in the rejection entered on 06/02/2025, Ott teaches that the ECM can be functionalized with either an azide ligand or an azide complementary reagent. Although Ott focuses on functionalizing the ECM with an azide ligand, Ott teaches that the ECM can also be functionalized with an azide complementary reagent as well (Ott para 0032). In view of this Madl teaches that ECM can be functionalized using the alkyne reactive chemistry, and also that depending on the type of biorthogonal reaction used, properties such as duration of the engineered ECM will be influenced (Madl pg. 2 col. 2 para 2 – pg. 3 col 1-col 2, Fig. 2 and Tab. 1). Therefore, a skilled artisan would have been able to recognize that using a biorthogonal reaction mechanism to immobilize the EV in an ECM such as that of Li would have improved the retention of EV in the ECM.
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references (Remarks pg. 7 para 3 to pg. 8 para 1), 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). In this case, Ott seeks use metabolic engineering approach to incorporate biomolecules into ECM using a click-reactive or biorthogonal chemistry approach to better improve the properties of the ECM Ott para 0117). Li’s method also seeks to improve the retention of EV in a target site by immobilizing EV in ECM by using a different mechanism (Li Abstract). Given that Ott and Madl teaches that ECM can be functionalized with an azide complimentary reagent and coupled to an azide that is attach to a biomolecule or an EV as thought by Wang using different types of biorthogonal mechanisms that will affect the properties of the engineered ECM, a skilled artisan would have been motivated to modify the teachings of Ott in view of Li, Madl and Wang to obtain the method or the biomaterial as claimed. Furthermore, the teachings, suggestion or motivation to combine references is just one way for determining obviousness (MPEP 2145 (X)(C), In determining the differences between the prior art and the claims, the question under 35 U.S.C. 103 is not whether the differences themselves would have been obvious, but whether the claimed invention as a whole would have been obvious (See MPEP 2141.02).
Conclusion
No Claims Allowed.
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to EMMANUEL LED YOUTCHOM PENDIE whose telephone number is (571)272-6313. The examiner can normally be reached Mon - Fri: 8AM - 5PM CST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joanna Hama can be reached at (571) 272-2911. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/EMMANUEL LED YOUTCHOM PENDIE/ Examiner, Art Unit 1647
/JOANNE HAMA/ Supervisory Patent Examiner, Art Unit 1647