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.
Claim Objections
Claim 4 is objected to because of the following informalities:
In line 2, “vinyl monomers is to the cyclic ketene acetal” should read “vinyl monomers to the cyclic ketene acetal.”
In line 2, “from between about” should read “from about.”
Appropriate correction is required.
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.
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 1-9 and 11 are 35 U.S.C. 103 as being unpatentable over Jacob et al (US 2020/0323777 A1) in view of Sun et al (CN 113754844 A, using the machine translation for the citations below) and Pesenti et al (100th Anniversary of Macromolecular Science Viewpoint: Degradable Polymers from Radical Ring-Opening Polymerization: Latest Advances, New Directions, and Ongoing Challenges, ACS Macro Letters, Vol. 9, pages 1812-1835, 2020).
Regarding Claims 1-3 and 6: 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 mixture is stirred/emulsified during the addition to the second solvent (para. 0335). 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)s and copolymers thereof (para. 0145).
Jacob is silent to the synthesis of the biodegradable polymer from a cyclic ketene acetal and a vinyl monomer taking place within the first organic solvent.
Sun teaches a biodegradable polymer nanomaterial (para. 0001) with a spherical/particle shape (para. 0009) 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 (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 and Jacob are analogous art because they are directed toward the same field of endeavor, namely the production of biodegradable polymer particles.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to synthesize a copolymer of a cyclic ketene acetal and a second monomer because it is a biodegradable polymer suitable for use in biomedical applications, which the invention of Jacob encompasses. The selection of a known material based on its suitability for its intended use supports a case of prima facie obviousness. See MPEP 2144.07.
Pesenti teaches that radical ring opening of cyclic ketene acetal monomers is facilitated by performing the polymerization in solution, rather than in bulk, which contributes to a larger proportion of biodegradable ester moieties in the resulting polymer (p.1814, Section 1.2). Pesenti and Jacob are analogous art because they are directed toward the same field of endeavor, namely biodegradable polymers.
It would have been obvious to synthesize a biodegradable polymer in solution, as taught by Sun, in order to increase the number of biodegradable moieties, as taught by Pesenti.
Regarding Claim 4: Sun teaches a molar ratio of the vinyl monomer to the cyclic ketene acetal of 4:1-1:1 (para. 0014).
Regarding Claim 5: Jacob teaches the first solvent may be acetone, ethanol, or isopropyl alcohol (para. 0202).
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 Jacob et al (US 2020/0323777 A1) in view of Sun et al (CN 113754844 A, using the machine translation for the citations below), Pesenti et al (100th Anniversary of Macromolecular Science Viewpoint: Degradable Polymers from Radical Ring-Opening Polymerization: Latest Advances, New Directions, and Ongoing Challenges, ACS Macro Letters, Vol. 9, pages 1812-1835, 2020), 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).
Jacob, Sun, and Pesenti 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.
Additional Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Ramstack (US 2013/0317208 A1) teaches a polymer particle production method.
Park (KR 2010/0027694A) teaches the use of PVP stabilizers in polymer particle production.
Kato (JP 2014/118528 A) teaches a solvent-exchange process.
Keßler et al (Simulating copolymeric nanoparticle assembly in the co-solvent method: How mixing rates control final particle sizes and morphologies, 22 September 2017, Polymer, Vol. 126, p.9-18) teaches the mixing of a solvent and a co-solvent for nanoparticle assembly.
Pesenti et al (Degradable Glycopolyester-like Nanoparticles by Radical Ring-Opening Polymerization, 2022, Biomacromolecules, vol. 23, p.4015-4028) teaches vinyl/CKA copolymer nanoparticles.
Dai et al (Biodegradable poly(ester)-poly(methyl methacrylate) copolymer for marine anti-biofouling, 2018, Organic Coatings, vol. 124, p.55-60) teaches a biodegradable CKA/MMA copolymer.
Wu et al (Synthesis, Characterization, and Hydrolytic Degradation of Copolymers of 2-Methylene-1,3-dioxepane with Ethylene and with Styrene, 1998, Journal of Environmental Polymer Degradation, Vol. 6, p.23-29) teaches vinyl/CKA copolymers.
Zhang et al (Biocompatible and degradable poly(2-hydroxyethyl methacrylate) based polymers for biomedical applications, 2012, Polymer Chemistry, Vol. 3, p.2752-2759) teaches CKA-based copolymers for use in biomedical applications.
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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/C.N.I./Examiner, Art Unit 1767
/MARK EASHOO/Supervisory Patent Examiner, Art Unit 1767