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 .
Priority
The instant claims are the national stage entry of PCT/CN2020/100525 filed 7 July 2020. Acknowledgement is made of the Applicant’s claim of foreign priority to foreign application CN202010011513.8 filed 6 January 2020. Should applicant desire to obtain the benefit of foreign priority under 35 U.S.C. 119(a)-(d) prior to declaration of an interference, a certified English translation of the foreign application must be submitted in reply to this action. 37 CFR 41.154(b) and 41.202(e). Failure to provide a certified translation may result in no benefit being accorded for the non-English application. The effective filing date of the instant claims is thus 7 July 2020.
Examiner’s Note
Applicant's amendments and arguments filed 23 September 2025 are acknowledged and have been fully considered. The Examiner has re-weighed all the evidence of record. Rejections and/or objections not reiterated from previous office actions are hereby withdrawn. The following rejections and/or objections are either reiterated or newly applied. They constitute the complete set presently being applied to the instant application. In the Applicant’s response, filed 23 September 2025, it is noted that claims 1-4, 6-7, 10-12, and 16-19 have been amended and find support throughout the specification. No new matter or claims have been added.
Status of the Claims
Claims 1-8 and 10-19 are pending.
Claim 7-8 and 10 are withdrawn.
Claims 1-6 and 11-19 are rejected.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 6 and 16-19 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. Instant claims 6 and 16-19 recite “…alginate derivatives… gelatin derivatives… collagen derivatives… hyaluronic acid derivatives…” and several additional derivatives of recited agents. The generic term "derivatives" encompass a potentially large groups of compounds; there is no disclosure of this term that would permit the determination of which compounds are within the scope of these compounds, what portion of the molecule, if any, is retained in common with the elected compound, which properties, if any, are required to satisfy the analog limitation, etc. A review of the disclosure identified no compounds identified as a derivative or analog of any compound, no reduction to practice, no identified partial structure, no discussion of physical or chemical properties, functional characteristics or method of making any derivative or analog of the recited species. The disclosure contains insufficient written description to demonstrate applicant was in possession of the genera of "derivatives" of these compounds; furthermore, the description does not place the public in possession of any of these generic groups of compounds. As such, claims 6 and 16-19 are rejected as lacking written description.
Claim Rejections - 35 USC § 112
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.
Claim 6 and 16-19 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. Claims 6 and 16-19 recites the limitation "wherein a crosslinking agent used for preparing the scaffold body…" There is insufficient antecedent basis for the limitation of the crosslinking agent in the claim.
Claim 6 and 16-19 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. A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claims 6 and 16-19 recites the broad recitations of lists of natural materials, synthetic materials, and crosslinking agents, and the claim also recites “the scaffold body is made of polyglycolic acid and fibrin, and the crosslinking agent is thrombin” which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Claim Rejections - 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.
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 11-15 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al. (US 2019/0030212) in view of Walter et al. (US 5,863,297).
Zhang teaches tissue constructs that include a scaffold having one or more channels, a hydrogel, and growth factors (abstract) useful as a human bone mimics [0041]. The construct may comprise biodegradable polylactic acid (PLA) fibers or gelatin-comprising hydrogels [0041]. The tissue construct can be fabricated into a scaffold that may include a central channel having a diameter from about 500 mm to about 2000 mm and may also comprise a plurality of peripheral channels [0049]. The scaffold may have an average pore size of from about 50 mm to about 300 mm and a porosity of between about 10% to 40% [0050]. The scaffold may have a compression modulus from about 0.03 to about 0.6 GPa [0051]. In one example, the construct is prepared by stacking units with a 200 mm line distance (interpreted as meaning diameter) to form a cylinder comprising a 2 mm channel in the center [0068]. The scaffold, when compressed, has a maximum strain of 20% [0071]. Zhang teaches that a person skilled in the art will recognize other components and configurations may be used [0036].
Zhang does not teach a Young’s modulus of 0.1 kPa to 10 MPa.
Walter teaches that is it desirable that a biodegradable implant designed for tissue ingrowth have mechanical properties similar to those of the tissue into which is it place, which is typically an elastic (Young’s) modulus of less than 1 MPa (col 2, lns 4-9). It is desirable that the implant be porous and more specifically have a Young’s modulus most preferably ranging from about 0.1 to about 10 MPa (col 4, lns 9-18). Walter also notes that suitable biodegradable polymers for use in bone implants can include PLA, polyglycolic acid (PGA), or mixtures thereof (col 5, lns 15-20) and that cross-linking agents may be used (col 10, lns 17-19).
It would have been prima facie obvious to prepare the porous, three-dimensional tissue scaffold implant for bone regeneration of Zhang which comprises a center channel, additional channels/pores, and growth factors. The composition can be made of PLA and/or gelatin, however Walter teaches that PGA is a suitable alternative biodegradable polymer for use in scaffolds. Generally, it is prima facie obvious to substitute one equivalent component or process for another, each of which is taught by the prior art to be useful for the same purpose (see MPEP 2144.06). Zhang teaches ranges that overlap with the claimed porosity and average pore diameter. The Example in Zhang teaches a 2 mm channel in the cylindrical scaffold, which makes a 2 mm (0.2 cm) overall length/height of the scaffold as obvious. The ratio of height to diameter would accordingly be 2:200 or 0.1:10.
Walter teaches that a biodegradable implant designed for tissue ingrowth should have a Young’s modulus most preferably ranging from about 0.1 to about 10 MPa. It should be noted that the compression modulus of Zhang is not the same thing as a Young’s modulus, thus Zhang is silent as to the desired Young’s modulus and therefore it would have been obvious to look to Walter for its teaching of a suitable range.
Regarding the porosity, pore diameter, and height and diameter of the scaffold, these values are taught in suitable ranges in Zhang but the art further teaches that alternative configurations may be used. As such, it would have been obvious to modify each of these parameters to read on the instant claims. That being said and in lieu of objective evidence of unexpected results, the parameters of the scaffold can be viewed as variables which achieve the recognized result of successfully preparing a bone mimic scaffold. The optimum or workable range of each of these parameters can be accordingly characterized as routine optimization and experimentation (see MPEP 2144.05 (II)B). “[Discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art.” In re Boesch, 617 F.2d 272, 276 (CCPA 1980).
The scaffold of Zhang is taught as having a compression strain of 20% and does not indicate damage or deformation, thus rendering obvious instant claims 5 and 13-15.
Thus, it would have been obvious to prepare the scaffold of Zhang with the Young’s modulus of Walter, thus rendering obvious instant claims 1-5 and 11-15.
Claims 1-6 and 11-19 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al. (US 2019/0030212) in view of Walter et al. (US 5,863,297) in view of Knothe Tate et al. (US 2005/0107887) in view of Guelcher et al. (US 2010/0068171).
Zhang and Walter, as applied supra, are herein applied in their entirety for the teaching of a scaffold having one or more channels, a hydrogel, and growth factors useful as a human bone mimics.
Zhang does not teach wherein the scaffold body is made of PGA and fibrin and the crosslinking agent is thrombin.
Knothe Tate teaches suitable cross-linking agents useful in scaffolds made from bone-endogenous materials [0043]. Thrombin is taught as being one such cross-linking agent [0043].
Guelcher teaches scaffolds for tissue engineering comprising biopolymers such as PLA or PGA [0005]. Guelcher further teaches that formulation as an injectable hydrogel, such as fibrin, supports bone ingrowth in vivo when combined with growth factors [0005].
It would have been prima facie obvious to prepare the bone scaffold of Zhang and Walter, as described above, which can comprise PLA or PGA along with a hydrogel. Since Guelcher teaches that fibrin hydrogel is useful for supporting bone ingrowth, it would have been obvious to select fibrin as the hydrogel of Zhang. Moreover, it would have been obvious to use thrombin as the cross-linking agent suggested by Walter. Generally, it is prima facie obvious to select a known material for incorporation into a composition, based on its recognized suitability for its intended use (see MPEP § 2144.07). The resulting composition, which comprises scaffolds comprising PGA, thrombin, and fibrin used together for supporting bone growth, would have been obvious to the skilled artisan, thus rendering obvious instant claims 1-6 and 11-19.
Response to Arguments
Applicant's arguments filed 23 September 2025 have been fully considered but they are not persuasive.
The pending rejections have been modified based on the amended claims. Xuenong and Kumaraswamy have been withdrawn as prior art and arguments against are thus considered moot and will not be further addressed.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 ANDREW S ROSENTHAL whose telephone number is (571)272-6276. The examiner can normally be reached M-F 8-5pm EST.
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/ANDREW S ROSENTHAL/ Primary Examiner, Art Unit 1613