DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after 16 March 2013, is being examined under the first inventor to file provisions of the AIA .
Status of the Claims
The listing of claims filed 23 September 2024, have been examined. Claims 1-10 are pending. Claim 3 is amended and is supported by the originally-filed disclosure.
Claim Objections
Claim 9 is objected to because of the following informalities:
Claim 9 claims "a sheath biosensor chip", wherein the term may be intended to list "a sheath" and "a biosensor chip" separately or “a sheath of a biosensor chip”. A “sheath” is generally not understood as modifying “biosensor chip.” The term "sheath biosensor chip" is not defined in the specification and is not a standard, recognized term of art within medical device manufacturing.
It is unclear whether the claim denotes a protective structural sheath for a biosensor chip, a biosensor chip housed inside a medical catheter sheath, or a single integrated device. The structural boundaries of this item cannot be ascertained by referencing the specification. Appropriate correction and/or clarification is required.
Claim Rejections - 35 USC § 112(b)
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 Applicant regards as his invention.
Claims 5 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, regards as the invention.
Claim 5 recites "a medical device" that is introduced twice within the same claim sentence ("wherein a surface of a medical device is coated with the copolymer..."). The second instance creates an ambiguous antecedent basis, as it is unclear whether it refers to the aforementioned device or a completely new one. It must be corrected to read "wherein a surface of the medical device...".
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 1-10 are rejected under 35 U.S.C. § 103 as being unpatentable over Kuo, et al. ("Surface modification with poly(sulfobetaine methacrylate-co-acrylic acid) to reduce fibrinogen adsorption, platelet adhesion, and plasma coagulation." Biomacromolecules. 2011;12(12):4348-56; hereinafter “Kuo”) in view of Yuya (WO2013164989A1; published 07 November 2013), and in further view of Wang et al. (CN113185630A; published July 30, 2021, hereinafter "Wang"), Kitano et al. (JP4961133B2; published 27 June 2012, hereinafter “Kitano”), and Xue and Liu (US20190129202A1; published 02 May 2019, hereinafter “Xue”).
Kuo teaches a zwitterionic copolymer based on poly(sulfobetaine methacrylate-co-acrylic acid) for biomedical surface modification. Specifically, Kuo discloses preparation of copolymers comprising sulfobetaine methacrylate (SBMA), a sulfobetaine zwitterionic group-containing polymerizable monomer, which corresponds to instant claimed monomer (A) and acrylic acid (AA) as a comonomer, which is a (meth)acrylic acid and which corresponds to instant claimed monomer (B) (Abstract; “Experimental Section,” synthesis of poly(SBMA-co-AA)).
Kuo further teaches that the resulting zwitterionic copolymer is useful for modifying biomedical surfaces to reduce fibrinogen adsorption, platelet adhesion, and plasma coagulation (Abstract; Introduction; Results and Discussion, “Surface characterization and blood compatibility”). Thus, Kuo teaches a polymer having a sulfobetaine group-containing monomer and a (meth)acrylic acid monomer.
Regarding instant claimed monomer (C), Kuo's copolymerization uses an ammonium persulfate (APS) free radical initiator which generates radicals to initiate polymerization. One of ordinary skill in the art would recognize that free-radical polymerization of vinyl monomers using APS can lead to the termination of polymer chains via combination or disproportionation, thus incorporating an acrylamide derivative, however Kuo does not explicitly teach distinct, intentional inclusion of an acrylamide derivative as a third comonomer component into the polymer backbone (instant claimed comonomer (C)).
Yuya teaches zwitterionic polymer compositions comprising hydrophilic monomers including acrylamide derivatives for preparing biocompatible polymer materials, including for contact lenses, to impart sufficient water wettability, lubricity and stain resistance to the surface of a substrate, such as a contact lens, without using an organic solvent (Abstract and ¶6). Yuya teaches polymerizable hydrophilic monomers including at least one selected from the group consisting of (meth)acrylamides and (meth)acrylates having an ionic group including carboxybetaine structure-containing methacrylates (methacryloyloxyethylcarboxybetaine, N-methacryloyloxyethyl-N, N-dimethylammonium-α-N-methylcarboxybetaine, etc.; ¶10 and ¶38). Therefore, Yuya teaches incorporation of acrylamide derivatives into zwitterionic polymer systems.
Wang teaches a biodegradable polyacrylamide-based polymer prepared from acrylamide, acrylic acid, carboxyl betaine methacrylic acid, and vinyl acetate in water under nitrogen with initiator (Abstract and claims 1 and 4). Wang Example 5 expressly discloses a polymerization recipe using acrylamide, acrylic acid, and carboxyl betaine methacrylic acid, with those monomers dissolved in deionized water and polymerized under N2 with ammonium persulfate/sodium bisulfite, thereby meeting the claim’s monomer components (A) carboxybetaine group monomer, (B) acrylic acid, and (C) acrylamide component, even though Wang also includes vinyl acetate as an additional monomer.
Further, Kitano teaches a medical material for a medical device such as a catheter, a guide wire, an artificial blood vessel, a hemodialysis membrane, an endoscope, or the like having a coating made of a biocompatible polymer, and a medical coating that can be suitably used for the coating (Description, ¶1). The biocompatible polymer comprises a betaine-type monomer having a carboxybetaine group (e.g., carboxybetaine methacrylate, CMB) and an acrylamide derivative (e.g., N,N-dimethylacrylamide, DMAA) as a comonomer (claims 1 and 2; page 3, ¶6; page 4, ¶2). Kitano teaches that incorporating an acrylamide derivative like DMAA provides excellent hydrophilicity and mechanical strength to the resulting coating (page 4, ¶3).
In addition, Xue teaches a copolymer coating for a contact lens (a medical device) comprising a zwitterionic monomer and a non-zwitterionic comonomer (Abstract), which can be carboxybetaine or sulfobetaine methacrylate (¶[0029]) and a mixture of methacrylic acid (a(meth)acrylic acid) (¶[0027]) and an acrylamide derivative such as N,N-dimethylacrylamide (¶[0029]).
Thus, it would have been prima facie obvious to one of ordinary skill in the art, prior to the instant effective filing date of the invention, to modify Kuo’s SBMA/acrylic acid copolymer by incorporating an acrylamide derivative as taught by Yuya, Kitano, and Xue to arrive at the instant claim 1 copolymer. One of ordinary skill in the art would have been motivated to make such a modification because acrylamide derivatives were known hydrophilic comonomers used in zwitterionic polymer systems to improve hydration, lubricity, polymer film formation, water compatibility, and biomedical coating performance as taught by Kitano and exemplified by Xue.
Kuo’s invention is directed to improving the hemocompatibility of surfaces by reducing fibrinogen adsorption, platelet adhesion, and plasma coagulation. Yuya teaches zwitterionic polymer compositions comprising hydrophilic monomers including acrylamide derivatives for preparing contact lenses for wettability, lubricity and stain resistance. Kitano and Xue similarly share the same fundamental goal of creating biocompatible, non-fouling coatings for medical devices. Kitano explicitly teaches that adding an acrylamide derivative like DMAA to a zwitterionic polymer improves the physical properties, such as hydrophilicity and mechanical strength, which are critical for durable medical coatings. Xue similarly teaches the combination of all three claimed monomers (sulfobetaine, (meth)acrylic acid, and acrylamide derivative) in a coating for a medical device.
The inventions are directed to the same field of hydrophilic (including zwitterionic), biocompatible polymer coatings. A person of ordinary skill in the art seeking to enhance the robustness and tune the hydrophilicity of Kuo’s binary anti-fouling copolymer would have been motivated by the express teachings of Yuya, Kitano, and Xue to incorporate an acrylamide derivative to achieve these known benefits. The combination of a zwitterionic monomer, a charged monomer like (meth)acrylic acid for functionalization/crosslinking, and a neutral hydrophilic monomer like an acrylamide derivative to modulate hydrophilicity and mechanical properties represents a simple variation/modification of known elements with predictable results according to their established functions, making it an obvious and predictable use of prior-art elements (see MPEP §2143 and §2144 and KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416-421 (2007)).
A skilled artisan would have a reasonable expectation of success because the references employ the same conventional free-radical polymerization chemistry to copolymerize monomers and acrylamide copolymerization with acrylic and zwitterionic vinyl monomers was well established. Accordingly, instant claim 1 would have been obvious.
Kuo teaches a wide range of monomer ratios for a poly(SBMA-co-AA) copolymer that encompass the instant claim 2 and 3 ranges, including 13 and 28 mol% SBMA and 20 mol% AA ((meth)acrylic acid) (Table 1), rendering the instant claimed ranges prima facie obvious because the ranges of a claimed composition overlap the ranges disclosed in the prior art (see In re Peterson, 315 F.3d 1325, 1329 (Fed. Cir. 2003). Furthermore, Kuo teaches varying the SBMA content in SBMA/acrylic acid copolymers to tune surface hydration, protein adsorption, and blood compatibility (copolymer synthesis and characterization discussion). Thus, Kuo teaches optimizing the relative amount of SBMA. Kuo teaches incorporation of acrylic acid into SBMA copolymers (synthesis section). The amount of acrylic acid is a formulation variable selected to control charge density, hydrophilicity, and coating performance.
Wang Example 5 uses 3 mol% carboxyl betaine methacrylic acid and 10 mol% acrylic acid, which fall squarely within claim 2’s recited 1 to 40 mol% range for monomer component (A) and claim 3’s recited 1 to 35 mol% range for monomer component (B).
A person of ordinary skill in the art would have been motivated to adjust the ratios to optimize the balance between fouling resistance (monomer A), functionalizability (monomer B), and mechanical properties/hydrophilicity (monomer C) as taught by Kitano and Xue using ratio ranges taught by Kuo and Wang. The optimization of a result-effective variable, such as monomer concentration, is routine experimentation well within the purview of the skilled artisan (see In re Aller, 220 F.2d 454, 456 (CCPA 1955). The specific ratios are merely the result of routine optimization of known process parameters.
Kuo dissolves the poly(SBMA-co-AA) copolymer in a solvent (e.g., phosphate-buffered saline, PBS, which is a water-based solvent) to create a coating solution for a medical device surface (Surface Coating section). Kuo’s polystyrene surface is a model for medical devices. Yuya teaches polymer compositions dissolved or dispersed in solvent systems for forming coatings (¶77). Therefore, a polymer composition containing the instant claimed copolymer and solvent would have been obvious.
Wang expressly discloses polymerizing monomer raw material with water under an inert gas and/or nitrogen atmosphere with initiator to perform copolymerization, and Example 5 gives a full worked procedure: dissolve acrylamide, acrylic acid, carboxyl betaine methacrylic acid, and vinyl acetate; purge with nitrogen; add initiator; heat; isolate, wash, dry, and granulate the polymer. Therefore, the claimed polymerization method would have been an obvious implementation of known polymerization conditions for the known monomer classes.
Kuo expressly teaches surface modification of biomedical materials using SBMA/acrylic acid copolymers (Abstract; Results section). The purpose is to create blood-compatible medical surfaces. Further, Kitano and Xue also explicitly teach medical compositions formed by dissolving the anti-fouling copolymer in a solvent and coating it onto medical devices such as contact lenses and catheters (Kitano ¶[0055] and Xue claims 1 and 10). The motivation to form a medical composition and a coated medical device from the copolymer of instant claim 1 is thus obvious. The copolymers are created for the express purpose of being dissolved and coated onto medical devices to impart biocompatibility. The reasonable expectation of success in forming a solution and coating is absolute, as it is the intended and demonstrated function of the reference compositions.
Kuo describes the method step of instant claim 6, a polymerization step, by free-radical polymerization of SBMA and acrylic acid in water to obtain the copolymer (Synthesis of poly(SBMA-co-AA) section). It would have been obvious to include an acrylamide derivative monomer in this step for the reasons stated above for instant claim 1. Because the underlying copolymer composition is obvious, the method of making it by conventional free-radical polymerization is equally obvious.
Further, Yuya teaches polymerization of zwitterionic monomers with acrylamide derivatives. The combination renders polymerization of the three monomer components obvious. One of ordinary skill in the art would use conventional free-radical polymerization techniques (see MPEP §2144.03).
Kuo also describes the steps of instant claims 7 and 8, the preparation step of mixing the copolymer with a solvent (PBS) and the coating step of bringing this composition into contact with a surface (polystyrene substrate; Surface Coating section). The methods of mixing the polymer with a solvent and coating a surface are explicit steps in the prior art's intended use. No unobvious modification to the conventional method is required. Therefore, instant claims 6-8 are rejected as obvious.
Kuo does not explicitly teach the coating of contact lenses; however, Xue explicitly teaches coating an ophthalmic lens, specifically a contact lens, with the copolymer composition. Yuya the use of the biocompatible polymer for contact lenses (¶6) and the entire purpose of Xue’s invention is to provide a coating for a contact lens (Abstract and ¶[0050]). It would have been obvious to one of ordinary skill in the art to coat a contact lens with the copolymer of claim 1, given the explicit teachings of Xue. Contact lenses represent a primary commercial application for highly hydrophilic, anti-fouling coatings, and the motivation to apply Kuo’s hemocompatible coating to an ophthalmic application with Yuya’s and Xue's contact lens-specific teachings would have been compelling.
To the extent the claim’s Markush group includes additional species such as skin covering material, wound covering material, skin protective material, drug carrier for skin, infusion tube, gas transport tube, drainage tube, blood circuit, covering tube, sheath, biosensor chip, heart-lung machine, and endoscope covering material, those species are merely predictable adjacent medical-device surfaces for application of the same known antifouling coating technology. One of ordinary skill in the art would apply Kuo’s known coating technology to this known medical device. The selection of a particular medical device is merely a predictable application (KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007)). A person of ordinary skill in the art would have a reasonable expectation of success because Xue provides a complete blueprint for applying this exact class of copolymer to a contact lens. Therefore, instant claims 9 and 10 are rejected as obvious.
In summary, it would have been prima facie obvious to one of ordinary skill in the art, prior to the instant invention effective filing date, to combine Kuo's hemocompatible binary copolymer with Yuya, Kitano, and Xue’s explicit teaching of incorporating a third acrylamide-derivative monomer to improve physical properties for medical device coatings involves no more than the simple substitution of one known element for another and the predictable use of prior art elements according to their established functions. The references are in the same field of endeavor (zwitterionic biomedical polymers), they address the same problem (hydrophilic, antifouling, biocompatible coatings), the modification involves predictable substitution/addition of known hydrophilic monomers, and a skilled artisan would have had a reasonable expectation of success. Accordingly, the claimed invention represents an obvious variation of known zwitterionic medical coating polymers.
Conclusion
No claims are allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to REBECCA L. SCOTLAND whose telephone number is (571) 272-2979. The examiner can normally be reached M-F 9:00 am to 5:00 pm EST.
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, Robert A. Wax can be reached at (571) 272-0623. 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.
/RL Scotland/
Examiner, Art Unit 1615
/Robert A Wax/Supervisory Patent Examiner, Art Unit 1615
Prosecution Insights