DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Applicant’s amendment and response filed on 8/17/2026 have been received and entered into the case. Claims 6, 13, 16, and 21-22 have been canceled. Claims 1-5, 7-12, 14-15, 17-20, and 23-25 are pending, Claims 4-5, 7-8, 17-20, and 23-25 have been withdrawn, and Claims 1-3, 9-12 and 14-15 have been considered on the merits, insofar as they read on the elected species of polyethylene glycol as the microgel-forming polymer, acrylate as the cross-linkable functional group, 2-hydroxy-4’-(2-hydroxyethoxy)-2-methylpropiophenone (Igracure 2959) as the radical initiator, and constant stirring at 100-1000 rpm as the stirring step. All arguments have been fully considered.
Withdrawn Rejections
Rejections under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, are withdrawn in view of applicant’s amendments.
Rejections of Claims 1-3, 9-10, 12 and 14-15 under 35 U.S.C. 103 as being unpatentable over Wu et al (Materials and Design. 2018;160:486-495.) in view of Burke et al (Polymers. 2019;11:1339.) are withdrawn in view of applicant’s amendments.
Rejections of Claim 11 under 35 U.S.C. 103 as being unpatentable over Wu et al (Materials and Design. 2018;160:486-495.) in view of Burke et al (Polymers. 2019;11:1339.) and Compaan et al (ACS Appl. Mater. Interfaces. 2019;11:5714-5726.) are withdrawn in view of applicant’s amendments.
Rejections of Claims 1-3, 9-12 and 14-15 on the ground of nonstatutory obviousness-type double patenting as being unpatentable over claims 1-4 of co-pending Application No. 18/009,144 (referred to as the ‘144 application) in view of Wu et al (Materials and Design. 2018;160:486-495.) and Compaan et al (ACS Appl. Mater. Interfaces. 2019;11:5714-5726.) are withdrawn since the co-pending Application No. 18/009,144 is abandoned.
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 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 of this title, 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.
Claims 1-3, 9-10, 12 and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al (Materials and Design. 2018;160:486-495.) in view of Burke et al (Polymers. 2019;11:1339.) and Toh (Thesis. 2011;1-41.).
The instant claims recite a method of forming a shear-thinning fluid gel composition comprising 0.5 to 20% w/v of a microgel particle-forming polymer dispersed in an aqueous medium, the method comprising the steps of: a) providing a microgel particle-forming polymer, wherein the polymer comprises a plurality of cross-linkable functional groups; b) dissolving the microgel-forming polymer provided in step a) in an aqueous medium at a concentration of 0.5 to 20% w/v to form a polymer solution; c) mixing the polymer solution formed in step b) with a radical initiator; and d) stirring the mixture until gelation is complete; wherein the viscosity and the elastic modulus of the shear-thinning fluid gel composition reversibly reduce when the gel is exposed to shear; and wherein the shear-thinning fluid gel composition at rest has an elastic modulus (G’) of 0.1 to 1000 Pa.
Wu teaches a method of forming a shear-thinning fluid gel composition (p.490 col left – para 1), comprising providing polyethylene glycol diacrylate (PEGDA) aqueous solution with different concentrations, e.g., 5.0 wt%, 10.0 wt%, and 15.0 wt% (Table 1), adding 2-hydroxy-4’-(2-hydroxyethoxy)-2-methylpropiophenone with a final concentration of 0.1 wt% (p.487 col right – para 2). Figure 2 shows significant shear-thinning pseudoplastic behavior, with increasing shear rate the bioink showed a decrease in viscosity (p.489 col right – para 4).
Wu does not teach stirring (claim 1), specifically constant stirring at 100 to 1000 rpm (claim 15).
However, Wu does teach PEG-based hydrogels using 2-hydroxy-4’-(2-hydroxyethoxy)-2-methylpropiophenone as a photo-initiator. Burke teaches PEG-based hydrogels using 2-hydroxy-4’-(2-hydroxyethoxy)-2-methylpropiophenone as a photo-initiator, wherein a mixture comprises a polymer and a photo-initiator is stirred at 200 rpm for 20 min (p.3 para 3).
Thus, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to constantly stir a mixture comprises a polymer and a photo-initiator at 100 to 1000 rpm, since such a stir step is routinely practiced in the art of forming PEG-based hydrogels, as evidenced by Burke. Moreover, before the effective filing date of the claimed invention, one of ordinary skill in the art would have been motivated by the cited reference and routine practice to constantly stir a mixture comprises a polymer and a photo-initiator at 100 to 1000 rpm, with a reasonable expectation for successfully forming a shear-thinning fluid gel composition.
Wu does not teach the method wherein the shear-thinning fluid gel composition at rest has an elastic modulus (G’) of 0.1 to 1000 Pa (claim 1).
However, Wu does teach PEGDA-based hydrogels as well as the claimed concentration of the microgel-forming polymer in the aqueous medium. Toh teaches it is expected that higher wt% concentration of PEGDA macromers in the preparation of PEGDA-based hydrogels lead to higher storage moduli of the hydrogel (p.41 para 1).
Thus, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to optimize wt% concentration of PEGDA macromers in the preparation of PEGDA-based hydrogels to obtain a desirable final product having optimized elastic modulus as a matter of routine experimentation, as evidenced by Toh. Moreover, before the effective filing date of the claimed invention, one of ordinary skill in the art would have been motivated by the cited reference and routine practice to optimize wt% concentration of PEGDA macromers in the preparation of PEGDA-based hydrogels to obtain a desirable final product having optimized elastic modulus, with a reasonable expectation of success.
References cited above do not teach the claimed concentration of photo- initator (claim 14).
However, Wu does teach the method comprises adding 2-hydroxy-4’-(2-hydroxyethoxy)-2-methylpropiophenone with a final concentration of 0.1 wt%.
Thus, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to optimize the concentration as a matter of routine experimentation. Generally, differences in concentration will not support patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration is critical. (MPEP 2144.05 II) Moreover, before the effective filing date of the claimed invention, one of ordinary skill in the art would have been motivated by the cited reference and routine practice to optimize the concentration with a reasonable expectation for successfully forming a shear-thinning fluid gel composition.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Wu et al (Materials and Design. 2018;160:486-495.) in view of Burke et al (Polymers. 2019;11:1339.) and Toh (Thesis. 2011;1-41.) as applied to claims 1-3, 9-10, 12 and 14-15 above, further in view of Compaan et al (ACS Appl. Mater. Interfaces. 2019;11:5714-5726.).
References cited above do not teach the aqueous medium is phosphate buffered saline (claim 11).
However, Wu does teach 3D bioprinting (Abstract). Compaan teaches 3D bioprinting (Abstract), wherein a fluid gel is prepared in phosphate buffered saline to prevent osmotic shock to printed cells, stabilize the pH, and match the ionic strength of ink formulations to minimize swelling (p.5716 col left – last para, col right – first para).
Thus, before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to incorporate phosphate buffered saline, since Wu and Compaan both disclose 3D bioprinting comprises a fluid gel, and Compaan specifically discloses that phosphate buffered saline in 3D bioprinting fluid gels enhances biocompatibility. Moreover, before the effective filing date of the claimed invention, one of ordinary skill in the art would have been motivated by the cited reference to incorporate phosphate buffered saline with a reasonable expectation for successfully forming a shear-thinning fluid gel composition.
Response to Arguments
Applicant argues that the formulations of Wu do not have an elastic modulus (G') at rest of 0.1 to 1000 Pa, as required by amended claim 1. However, these arguments are moot since those rejections are withdrawn in view of applicant’s amendments.
Applicant argues that the claimed fluid gel compositions according to the present application have been designed for use as eye drops to be applied to the ocular surface acting as a transparent barrier, and that it can be seen how the shear-thinning fluid gel compositions of the amended claims, being formed by the claimed method comprising shear-mixing during the sol-gel transition, are specifically designed for use as eye drops to be applied to the ocular surface and act as a transparent barrier.
These arguments are not found persuasive because applicant’s arguments regarding “designed for use as eye drops” appear to have no connection to the subject at issue, since rejected claims do not require “eye drops”.
Applicant argues that Wu does not disclose or suggest that stirring was used during the gelation process as required by step d) of claim 1, that Burke does not disclose stirring of the polymer sol throughout the gelation process as required in amended claim 1, and that Burke does not teach the formation of a shear-thinning fluid gel composition comprising a microgel particle-forming polymer dispersed in an aqueous medium.
These arguments are not found persuasive because rejected claims recite “stirring the mixture until gelation is complete” (in claim 1d), “wherein the stirrig in step d) is carried out: … ii) by constant stirring at 100 to 1000 rpm.” Therefore, constant stirring at 100 to 1000 rpm results in “gelation is complete”. Burke does teach stirring the mixture at 200 rpm for 20 min (constant stirring at 100 to 1000 rpm), which read on stirring the mixture until gelation is complete. The patentable weight is carried in method steps in method claims. Applicant may amend claims to better distinguish claimed method steps from the prior art, not just characteristics for each step.
Applicant argues that Compaan does not remedy the deficiencies of Wu and Burke with respect to the features of amended claim 1. However, these arguments are moot since those rejections are withdrawn in view of applicant’s amendments.
Conclusion
No claims are allowed.
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 extension fee 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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LYNN Y FAN whose telephone number is (571)270-3541. The examiner can normally be reached on M-F 7am-4pm.
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, Curtis Mayes can be reached on (571)272-1234. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/Lynn Y Fan/
Primary Examiner, Art Unit 1759
