Prosecution Insights
Last updated: August 18, 2026
Application No. 18/277,676

GUEST-HOST SUPRAMOLECULAR ASSEMBLY OF INJECTABLE HYDROGEL NANOFIBERS FOR CELL ENCAPSULATION

Final Rejection §103§112
Filed
Aug 17, 2023
Priority
Feb 17, 2021 — provisional 63/150,328 +1 more
Examiner
BERKE-SCHLESSEL, DAVID W
Art Unit
1651
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
University of Virginia Patent Foundation
OA Round
2 (Final)
67%
Grant Probability
Favorable
3-4
OA Rounds
0m
Est. Remaining
98%
With Interview

Examiner Intelligence

Grants 67% — above average
67%
Career Allowance Rate
497 granted / 746 resolved
+6.6% vs TC avg
Strong +32% interview lift
Without
With
+31.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
46 currently pending
Career history
791
Total Applications
across all art units

Statute-Specific Performance

§101
9.5%
-30.5% vs TC avg
§103
37.9%
-2.1% vs TC avg
§102
15.8%
-24.2% vs TC avg
§112
24.9%
-15.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 746 resolved cases

Office Action

§103 §112
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 Arguments In the Response, dated 4/30/2026, the Applicant has provided amendments to the claims, and Arguments directed to the previous rejections and objections. With respect to the objections to the specification, the Applicant has provided all necessary amendments and the objections to the specification are withdrawn. Additionally, the Applicant has provided amendments to the claims to allow for the withdrawal of the objections to the claims. On page 18 of the Applicant’s Arguments, the Applicant discusses the 35 USC 112(b) rejections of claims 7, 9, and 10. Based upon the provided amendments, and the Applicant’s Arguments, these 35 USC 112(b) rejections are withdrawn. On page 18 of the Applicant’s Arguments, the Applicant contends that claim 16 is definite and understandable by the artisan. First, it must be noted that the included “optional” limitations are considered exemplary, and do not provide for patentable weight; if the Applicant wants these limitations given weight, they must be clearly claimed as actual limitations. Second, the preamble of the claim clearly states that the formulation is “injectable.” Third, the claim states that the “injectable composition is configured for injection.” The claim was considered indefinite because prior to stating that the composition is configured for injection, it was already made clear that the composition was formulated for injection. It is unclear how the claimed “configured for injection” changes the limitation of an “injectable formulation,” and the associated ingredients of the composition. Since it is unclear how this configuration changes the parent claim, the limitation is considered indefinite; however, based upon how the Applicant argues the claim, if it is not rejected under 35 USC 112(b), it would be rejected under 35 USC 112(d), since it does not appear to further limits the parent claim. This was made clear in the previous rejection. On page 19 of the Applicant’s Arguments, the Applicant discusses the 35 USC 112(d) rejection of claim 13. The Applicant’s arguments are reasonable, and the rejection is withdrawn. However, the Applicant’s arguments further bolster the need for claim 16 to be rejected under either 35 USC 112(b) or 112(d). On page 20 of the Applicant’s Arguments, the Applicant states that there would be no motivation to combine Burdick and Wang. To the contrary, not only do Burdick and Wang teach overlapping compounds, they both are explicitly providing materials for the same types of treatment, and as such, are directly within the same field of biomaterials and wound dressings. See Burdick, column 14, lines 4-15; Wang, page 657, “Regenerative medicine, tissue engineering and drug delivery” section. As such, the motivation would clear to the ordinary artisan, since it would appear as though Burdick is not only compatible with Wang, but there is implicitly motivation to try, as the compounds of Burdick are known to be used in the field of tissue engineering. If the Applicant can show that the process of electrospinning the composition of Burdick results in a functionally non-obvious behavior, this would be notable and could be used as evidence of non-obviousness; however, Burdick shows a composition that is known and useful for the field of tissue engineering, while Wang provides for electrospinning of overlapping compounds, which are also used in the field of tissue engineering. On page 21 of the Applicant’s Arguments, the Applicant argues that there is no articulated reasoning for combining Seon-Lutz with the other two references. Seon-Lutz is linked to Burdick and Wang because they all are explicitly describing overlapping compounds used in some for of wound dressing. If Seon-Lutz shows a composition that has utility for wound dressing, there would be implicit motivation to try Seon-Lutz’s method on other compositions used for the purpose of wound dressing. If the Applicant can provide evidence that the claimed limitation provides for unexpected changes to the composition, this would provide for evidence of non-obviousness over the combination of cited references. No claims allowed. All claims are rejected for the reasons provided above, and the reproduced rejections, below. 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 16 is 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. Claim 16 is indefinite because it is unclear what specifically must be done in order to configure the material to be injectable into a tissue. It is unclear if the claim is trying to include additional ingredients, or if the claim is merely restating the injectability of the material, and should be rejected under 35 USC 112(d). 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 1-19 and 26-31 are rejected under 35 U.S.C. 103 as being unpatentable over Burdick, et al (US Pat. 9,827,321) and Wang, et al (Materials Science & Engineering C, 101, 650-659, 2019) and evidenced by Tan, et al (Journal of Biomedical Materials Research Part A, 87, 1034-1043, 2008). Burdick teaches a hydrogel composition comprising two separate hyaluronic acid backbones, wherein one backbone supports a guest adamantane, and the other supports a host β-cyclodextrin. Burdick indicates that the composition is capable of shear-thinning, which means that it would be an injectable composition. See column 3, lines 5-14. Burdick does not state that the composition has been subjected to an electrospinning apparatus, nor is it stated that the material is fibrous. Wang provides a review paper that discusses the state-of-the-art, with respect to electrospinning particular compounds. Notably, Wang indicates that polymers with pendant β-cyclodextrin have been successfully electrospun. Wang indicates that both β-cyclodextrin and adamantane can be grafted onto hyaluronic acid backbones, and further suggests that this material can be electrospun. See page 654, right column, first [full] paragraph. As such, Wang shows that Burdick’s material should be predictably compatible with electrospinning methods, and further provides for an explicit motivation to try. Wang does not state that this material would be expected to be a fibrous and injectable composition. However, it must be noted that Burdick explicitly stating that the material is a shear-thinning material would suggest that the electrospun material of Wang must also be injectable, as it is composed of the same materials. Tan is provided to indicate that if a material is electrospun, it would necessarily be considered “fibrous.” See page 1034, “Introduction” section. Therefore, there is a reasonable expectation that the material that Wang suggests must also be “fibrous.” With respect to claims 1 and 13, Burdick teaches the claimed material, but does not teach or suggest electrospinning. Wang teaches a material that is the same as Burdick’s and suggests that the material could be electrospun. Burdick notes that the material is an injectable hydrogel, and Tan indicates that an electrospun material is fibrous. With respect to claim 2, Burdick indicates that the hyaluronic acid backbone can be methacrylate functionalized. See column 3, lines 15-20. With respect to claim 3, Burdick teaches crosslinking with a UV-based photo-initiator. See column 3, lines 12-14. With respect to claims 4 and 5, although both Burdick and Wang are silent with respect to the hydrophobicity of the composition, both references explicitly describe the same guest-host interaction as that claimed. As such, it would be reasonable to suggest that the claimed interaction is inherent a composition comprising 2 separate hyaluronic acid backbones, one with adamantane, and the other with β-cyclodextrin as pendant groups. See MPEP 2112. With respect to claim 6, Burdick teaches a 1:1 ratio. See column 3, line 28. With respect to claims 7 and 9, as discussed above, Burdick teaches a shear-thinning material. Since Burdick teaches one of the main physical properties claimed, and describes the claimed material, it can be reasonably asserted that Burdick’s material possesses the same properties as those claimed. With respect to claim 8, although Burdick does not state the claimed constant, Burdick describes the same composition with the same ratio. As such, Burdick’s material likely possessed the claimed constant. With respect to claim 10, Burdick indicates that the material can be configured to receive cells. See column 1, lines 60-67. With respect to claim 11, Burdick suggests that the material would have ECM-like stability. See column 1, lines 27-32. With respect to claim 12, Burdick appears to suggest inclusion of the same ligands. See column 10, lines 58-67. With respect to claim 14, Burdick suggests the inclusion of encapsulated cells. See column 1, lines 60-67. With respect to claim 15, although Burdick does not state the post injection survival rate, there is nothing claimed to suggest that Burdick’s rate is any different. With respect to claims 16 and 17, Burdick indicates that the material is injectable. Although the potential flow rate of the material is not described, there is nothing in the claims to suggest that the material of Burdick would flow any differently. With respect to claim 18, Burdick indicates that the material is dispersed in water. See column 5, lines 22-30. Water is an acceptable carrier. With respect to claim 19, although Burdick does not state the claimed physical properties, Burdick describes the same composition and as such, must describe a composition that possesses the same properties. With respect to claims 26-30, Burdick teaches the same methods of treating tissue. See column 1, lines 15-33. With respect to claim 31, Burdick suggests the inclusion of any number of stem and progenitor cells. See column 13, lines 1-9. Based upon this, the ordinary artisan would understand that any number of tissues could be treated, including those of the musculoskeletal system. Claims 20-25 are rejected under 35 U.S.C. 103 as being unpatentable over Burdick, et al (US Pat. 9,827,321) Wang, et al (Materials Science & Engineering C, 101, 650-659, 2019) and Seon-Lutz, et al (Carbohydrate Polymers, 207, 276-287, 2019) and evidenced by Tan, et al (Journal of Biomedical Materials Research Part A, 87, 1034-1043, 2008). See the discussion of Burdick, Wang, and Tan, above. As discussed above, Wang describes methods of electrospinning the claimed composition, but performed the electrospinning method in air. Seon-Lutz provides for methods of electrospinning hyaluronic acid, with β-cyclodextrin is capable of being successfully, and predictably electrospun into a “polymer solution” of water. Seon-Lutz performs this method as a means of making a wound dressing. See page 276, “Abstract” section. Based upon Seon-Lutz’s evidence that the claimed material can be subjected to an electrospinning method, wherein the material is spun into a polymer solution, and the fact that Seon-Lutz provides motivation to perform the claimed method, the ordinary artisan would find the claimed method to be obvious. See page 276 and 277, “Introduction” section. With respect to claim 20, Burdick teaches the claimed polymers and methods of UV crosslinking. Wang suggests that the material of Burdick can be electrospun, and it would have utility. Seon-Lutz shows that the material of Burdick can be electrospun into a polymer solution, and provides motivation to perform this method step. With respect to claim 21, Burdick includes the same anhydrides. See column 12, line 35. With respect to claim 22, Burdick describes the same preparation method. See columns 18 and 19. With respect to claim 23, since Seon-Lutz does not explicitly electrospin the claimed material, the claimed parameters would likely be slightly different. However, the ordinary artisan possesses ample knowledge of electrospinning methods and would understand that all compounds must undergo some amount of obvious optimization of the parameters. With respect to claim 24, Burdick shows a time-course of UV crosslinking’s affects on the composition’s physical properties. See figure 10B. The figure shows crosslinking data that includes the claimed time range. Additionally, since Burdick teaches the same photoinitiator, Burdick used the same wavelengths. With respect to claim 25, there is nothing non-obvious about modifying the size of the electrospun fibers. Conclusion 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 DAVID W BERKE-SCHLESSEL whose telephone number is (571)270-3643. The examiner can normally be reached M-F 8AM-5:30PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Melenie Gordon can be reached at 571-272-8037. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /DAVID W BERKE-SCHLESSEL/Primary Examiner, Art Unit 1651
Read full office action

Prosecution Timeline

Aug 17, 2023
Application Filed
Oct 30, 2025
Non-Final Rejection mailed — §103, §112
Apr 30, 2026
Response Filed
Jul 06, 2026
Final Rejection mailed — §103, §112 (current)

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Prosecution Projections

3-4
Expected OA Rounds
67%
Grant Probability
98%
With Interview (+31.9%)
2y 10m (~0m remaining)
Median Time to Grant
Moderate
PTA Risk
Based on 746 resolved cases by this examiner. Grant probability derived from career allowance rate.

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