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
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Response to Amendment
The amendments filed on June 11, 2026 have been entered. Claims 1-3 and 6-11 are pending in the application.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 1-3, 6-9 and 11 are 35 U.S.C. 103 as being unpatentable over Sun et al (CN 113754844 A, using the machine translation for the citations below) in view of Jacob et al (US 2020/0323777 A1) and Komatsu et al (JP 2021/075707 A, using the machine translation for the citations below).
Regarding Claims 1-3 and 6: Sun teaches a method of making a biodegradable polymer nanomaterial (para. 0001) with a spherical/particle shape (para. n0009) for drug release applications (para. n0002) comprising a copolymer of a cyclic ketone acetal monomer and a second polymeric monomer such as styrene or methyl methacrylate (para. 0007), which are polymerized in the presence of an initiator/radical source and an organic solvent such as ethanol or isopropanol (para. 0017, n0011) through a radical ring-opening polymerization process (para. 0029). The radical source is AIBN (para. 0060), and the cyclic ketene acetal may be 2-methylene-1,3-dioxepane (para. 0014). Sun teaches a molar ratio of the vinyl monomer to the cyclic ketene acetal of 4:1-1:1 (para. 0014). However, Sun is silent to emulsifying the reaction mixture in a second organic solvent.
Jacob teaches a process for preparing polymer particles, wherein the process comprises a step of providing a polymer dispersed in a first organic solvent and a step of adding the mixture to a second organic solvent (para. 0029-0030), wherein the first solvent is acetone, ethanol, or isopropyl alcohol (para. 0202) and wherein the mixture is stirred/emulsified during the addition to the second solvent (para. 0335), wherein the nanoprecipitation/adding to the second solvent provides better loading of drugs into nanoparticles (para. 0092). Jacob further teaches that the polymer is biodegradable (para. 0142) and that the scope of the term “biodegradable” is intended to include all relevant biodegradable polymers (para. 0146), as well as polyesters such as poly(lactic acid) and copolymers thereof (para. 0145). Sun and Jacob are analogous art because they are directed toward the same field of endeavor, namely the production of biodegradable polymer particles for drug delivery applications. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to add a step of emulsifying the polymer of Sun in a second solvent in order to produce polymer particles with a higher drug loading.
Sun is silent to the first solvent being acetonitrile.
Komatsu teaches the copolymerization of a cyclic ketene acetal through a radical ring-opening polymerization process (para. 0013), wherein the polymerization is performed in a solvent such as methanol, ethanol, or acetonitrile (para. 0044). Komatsu establishes equivalency of methanol, ethanol, and acetonitrile as polymerization solvents. Sun and Komatsu are analogous art because they are directed toward the same field of endeavor, namely cyclic ketene acetal polymer synthesis. As instant specification is silent to unexpected results, it would have been obvious to one of ordinary skill in the art at the time the invention was made to substitute the methanol or ethanol of Sun with acetonitrile since such modification would have involved a mere substitution of known equivalent materials. A substitution of known equivalent structures is generally recognized as being within the level of ordinary skill in the art. See MPEP § 2144.06.
Regarding Claims 7-8: Sun teaches a stabilizer/first polymer comprising PVP/homopolymer of N-vinylpyrrolidone (para. 0010) which is added to the monomer mixture (para. 0017). Sun does not teach that the PVP is added to the monomers before the addition of the solvent; however, the selection of any order of mixing ingredients is prima facie obvious. MPEP 2144.04(IV)(C). Sun further teaches that the PVP facilitates the formation of block copolymers and nanostructured materials (para. n0011-n0012) and that its presence/content is used to control the morphology of the nanomaterials (para. n0015).
Regarding Claim 9: Sun teaches a working example comprising 100mg of PVP, 0.2mg of AIBN, 1.04g of a vinyl monomer, 405mg of a cyclic ketene acetal monomer, and 1ml of an organic solvent (para. 0060). Based on calculations, the PVP is present at 4.3 wt% of the reaction mixture.
Regarding Claim 11: Jacob teaches that the second solvent/anti-solvent may be heptane (para. 0210).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Sun et al (CN 113754844 A, using the machine translation for the citations below) in view of Jacob et al (US 2020/0323777 A1), Komatsu et al (JP 2021/075707 A, using the machine translation for the citations below), and Dominguez-Delgado et al (Effects of Process and Formulation Parameters on Submicron Polymeric Particles Produced by a Rapid Emulsion-Diffusion Method, 10 January 2022, Nanomaterials, Vol. 12, p.229).
Sun, Jacob, and Komatsu teach the limitations of claim 1, as set forth above. Jacob further teaches that the rate of addition of the polymer mixture into the second organic solvent is preferably slow (para. 0213). However, Jacob is silent to the dropwise addition of the polymer mixture into the second organic solvent.
Dominguez-Delgado teaches an emulsion-diffusion method of polymer particle production (Abstract) comprising the dropwise addition of a polymer solution into a second solvent, wherein the second solvent is constantly stirred/emulsified (p.5, Section 2.2.2, first paragraph). Dominguez-Delgado sets forth the dropwise addition as a critical parameter in obtaining a unimodal particle size (p.4, last paragraph). Dominguez-Delgado and Jacob are analogous art because they are directed toward the same field of endeavor, namely biodegradable polymer particle production. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to add the polymer mixture of Jacob to the second organic in a dropwise fashion in order to obtain a uniform particle size distribution.
Response to Arguments
Applicant's arguments filed June 11, 2026 have been fully considered but they are not persuasive.
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, 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, one of ordinary skill in the art would be motivated to use the process of Jacob to make the CKA-vinyl particles of Sun because the CKA-vinyl polymers are highly biodegradable, which is a desirable feature set forth by Jacob. Nevertheless, the rejection above has been adjusted for clarity.
The new limitation of the first solvent being acetonitrile is overcome by Komatsu, as set forth above.
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.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CAITLIN N ILLING whose telephone number is (571)270-1940. The examiner can normally be reached Monday-Friday 8AM-4PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Mark Eashoo can be reached at (571)272-1197. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/C.N.I./Examiner, Art Unit 1767
/MARK EASHOO/Supervisory Patent Examiner, Art Unit 1767
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