DETAILED ACTION
This action is in response to the amendments and remarks filed 10/20/2025, in which claim 8 has been amended, and claims 1-14 and 16-21 are pending and ready for examination.
Claim Objections
Applicant is advised that should claim16 be found allowable, claim 19 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m).
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, 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 1-5, 7-9 and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over Mansur et al., Malaysian Journal of Fundamental and Applied Sciences Vol. 14, No. 3 (2018) 343-347 (hereinafter “Mansur”) in view of US 5,418,061 (hereinafter “Parham”), Rajesha Kumar, Polysulfone-Chitosan blend ultrafiltration membranes preparation, characterization, permeation and antifouling properties, RSC Adv., 2013,3, 7855-7861 (hereinafter "Kumar") and US 2012/0226258 A1 (hereinafter "Otto").
Regarding Claims 1, 5 and 8 Mansur discloses a process for preparing a porous hollow fiber ultrafiltration membrane for hemodialysis, comprising the production of a microporous hollow fiber support membrane, wherein the production of the microporous hollow fiber support membrane comprises the steps of
a) forming a polymer solution comprising polysulfone, and polyvinylpyrrolidone; and N-methyl-2-pyrrolidone;
b) extruding the polymer solution through an outer ring slit of a nozzle with two concentric openings into a precipitation bath (this structure is inherent to the disclosed spinneret, “[t]he dope solution extruded out from the dope reservoir and passed through a spinneret with a dimension of 0.3 mm and 0.6 mm for inner and outer dimension”); simultaneously
c) extruding a center fluid through the inner opening of the nozzle (“bore fluid was channeled into the spinnerets”);
d) washing the membrane obtained (the two coagulation bath are considered to wash the membranes);
wherein the polymer solution comprises from 18 wt.%, relative to the total weight of the polymer solution, of polysulfone; and from 3 or 8 wt.%, relative to the total weight of the polymer solution, of polyvinylpyrrolidone (see Abstract, Sec. Dope Solution preparation)
Mansur does not disclose (1) 10 to 15 wt.% polysulfone, relative to the total weight of the polymer solution polysulfone, or (2) that the support membrane comprises chitosan i.e. in the polymer dope solution, from 0.05 to 0.6 wt.%, relative to the total weight of the solution, and drying the membrane after washing, or (3) grafting of an anticoagulant onto at least one surface of the support membrane.
However, with regard to (1) wt% polysulfone in the dope, Parham discloses forming a similar hollow fiber membrane, which may be used for blood or plasma, formed from polysulfone and optionally including a PVP additive (C4/L38-42, C6/L5-12), wherein it is disclosed that the concentration of polysulfone in the solvent can range from 8-35 wt% (C5/L3-13).
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Mansur by using 8-35 wt% PS in the dope solution as disclosed by Parham because this involves the simple substitution of known PS concentrations used in hollow fiber dope solutions for forming hollow fiber membrane used in the biomedical applications to obtain the predictable result of forming a successful hollow fiber.
With regard to (2) chitosan and drying, Kumar discloses a similar PS ultrafiltration membrane comprising biocompatible chitosan blended with the PS to form the membrane which results in improved antifouling of the membrane, wherein 2.5 and 5 wt% chitosan is used in the final membrane, and where it is further disclosed that the membrane is dried after washing it during formation (Abstract, Sec. 2.1.).
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Mansur in view of Parham by including chitosan in the polymer dope solution in an amount which results in 2.5-5 wt% chitosan with regard to polysulfone in the final membrane and drying the membrane after washing it as disclosed by Kumar because including chitosan in similar polysulfone membranes results in improved biocompatibility and antifouling of the membrane, and because it known to dry similar membranes after formation before used and/or storage.
Thus in combination the chitosan would be included in the dope solution in an amount of 2.5-5wt% of the amount of polysulfone, which is included in the dope solution at 8-35 wt% (supra), and thus 0.2-1.75 wt% chitosan would have been obvious to use in the dope solution.
With regard to (3) anticoagulant coating, Otto discloses a porous hollow fiber membrane having a hemocompatible coating applied/grafted to the inner or outer surfaces of the hollow fiber membrane [0083], wherein the hemocompatible coating may be heparin [0084]-[0085] (i.e. an anticoagulant immobilized thereon); wherein the membrane may comprise a blend of polymers [0046] wherein polysulfone, poly-n-vinylpyrrolidone and chitosan are among the polymers which may be blended to form the membrane [0045]. Wherein the coating “serves the function of removal of toxins of biological and chemical synthetic origin, their metabolites and degradation products of blood, blood substitutes or solutions for the introduction into the human and/or animal blood circulation” [0083].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Mansur in view of Parham and Kumar by grafting a coating of the anticoagulant heparin on the hollow fiber membranes inner and/or outer surface as disclosed by Otto in order to improve the hemocompatibility of the membrane when used with blood and because it “serves the function of removal of toxins of biological and chemical synthetic origin, their metabolites and degradation products of blood, blood substitutes or solutions for the introduction into the human and/or animal blood circulation” [0083].
Since the range(s) disclosed overlaps the range(s) claimed, the range(s) recited in the claim is/are considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range(s) that corresponds to the claimed range. See MPEP 2144.05(I).
With specific regard to claim 1, the combined of Mansur in view of Parham, Kumar and Otto results in a membrane having an anti-coagulant immobilized thereon, the membrane comprising a blend PS, PVP and chitosan.
Regarding Claim 2-3 and 13 Mansur in view of Parham, Kumar and Otto discloses the process of any one of claims 1 and 8, wherein the anticoagulant is disclosed to be heparin Otto [0084]-[0085], and while it is not disclosed to be unfractionated heparin, the Examiner takes official notice that “unfractionated heparin” is the standard heparin and it would therefore have been obvious to use “unfractionated heparin” when “heparin” is disclosed.
Regarding Claim 4 Mansur in view of Parham, Kumar and Otto discloses the membrane of claim 1, but is silent to the concentration of the anticoagulant on the porous hollow fiber, and therefore it is not disclosed that is in the range of from to 1,000 to 5,000 IU/m2.
However, it would have been obvious to one of skill in the art that the amount of the heparin coating would effect both the flow through the membrane (by providing resistance or clogging pores) as well as the hemocompatibility of the membrane (since this is disclosed to imparted by the coating) and therefore the concentration of the anticoagulant on the porous hollow fiber is a variable which achieves a recognized result, and it would therefore have been obvious for one of skill in the art to optimize this variable through routine experimentation, by using values including those within the scope of the present claims, so as to produce desired end results. See MPEP § 2144.05 (B).
Regarding Claims 7 and 9 Mansur in view of Parham, Kumar and Otto discloses the process of claim 8, wherein the chitosan has a degree of deacetylation of from 75-85% (Kumar Sec. 2.1.).
Regarding Claim 12 Mansur in view of Parham, Kumar and Otto discloses the process of any one of claims 8, wherein the anticoagulant is grafted onto the at least one surface of the support membrane by contacting an aqueous solution of the anticoagulant with the at least one surface of the support membrane (see the rejection of claim 8 and Otto Example 5 [0133]).
Regarding Claim 14 Mansur in view of Parham, Kumar and Otto discloses a filtration and/or diffusion device comprising a plurality of porous hollow fiber membranes according to claim 1 (Mansur discloses potting 10 fibers in a membrane module and using it in an ultrafiltration system for water separation, Sec. Performance test of PSf/PVP hollow fiber membrane).
Claims 6, 16 and 19-21 are rejected under 35 U.S.C. 103 as being unpatentable over Mansur in view of Parham, Kumar and Otto and further in view of Im.
Regarding Claim 6, 16 and 19 Mansur in view of Parham, Kumar and Otto discloses the membrane of claim 1, wherein the chitosan is disclosed to be “low molecular weight (Kumar Sec. 2.1.). but the specific molecular weight is not disclosed.
However Im discloses low molecular weight chitosan has a molecular weight of from 50-190 kDa [0058].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the membrane of Mansur in view of Parham, Kumar and Otto by using chitosan having a molecular weight of from 50-190 kDa as disclosed by Im because this involves the simple substitution of known low molecular weight chitosan molecular weights to obtain the predictable result of forming a successful hollow fiber membrane.
Regarding Claim 20-21 Mansur in view of Parham, Kumar, Otto and Im discloses the process of claim 19, and the additional limitations “forming the polymer solution involves dissolving the chitosan in lactic acid”, and “wherein the chitosan is dissolved in a 90% w/w aqueous solution of lactic acid” are directed to how the membrane is formed, i.e. product-by-process limitations. Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process. MPEP 2113. The additional limitations to “forming the polymer solution involves dissolving the chitosan in lactic acid”, and “wherein the chitosan is dissolved in a 90% w/w aqueous solution of lactic acid” are not seen to be detailed enough to result in a membrane having different structure then then membrane as recited in claims 1, 6 and 19 and disclosed by Mansur in view of Parham, Kumar, Otto and Im.
Claims 10-11 and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Mansur in view of Parham, Kumar and Otto further in view of WO 2020113342 A1 (hereinafter “Arkoun”).
Regarding Claim 10-11 and 17-18 Mansur in view of Parham, Kumar and Otto discloses the process of claim 8 and 9, wherein the chitosan is disclosed to be dissolved in acetic acid before addition to the polymer solution (Kumar Sec. 2.1.) but does not disclose (claims 10 and 17) forming the polymer solution involves dissolving the chitosan in lactic acid, or (claims 11 and 18) wherein the chitosan is dissolved in a 90% w/w aqueous solution of lactic acid.
However Arkoun discloses a method of forming a chitosan coating solution where chitosan is dissolved into solution where lactic acid, including as a 90% w/w aqueous solution of lactic acid, is disclosed to be an alternative to acetic acid for dissolving chitosan, [0005] [0124].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Mansur in view of Parham, Kumar and Otto by substituting the acetic acid solution for dissolving the chitosan with a 90% w/w aqueous solution of lactic acid before addition to the polymer solution as disclosed by Arkoun because this involves the simple substitution of known chitosan solvents to obtain the predictable result of forming a successful membrane.
Response to Amendment
The previous 35 U.S.C. 112(b) rejection of claim 8 is withdrawn in view of the Applicants’ arguments and amendments.
Response to Arguments
Applicant's arguments filed 10/20/2025 have been fully considered and they are persuasive in part.
Applicants’ arguments directed to the 103 rejection citing Otto as the primary reference are persuasive; the Examiner agrees that a person of ordinary skill in the art would not have been motivated to pick and blend the specific polymers recited from Otto alone.
In response to Applicants’ argument that “[g]iven the disparate, separate teachings of each of the four references, Applicant respectfully asserts that a person of ordinary skill in the art would not be motivated to combine the teachings and arrive at the claimed invention”; the Examiner disagrees. Applicants’ argue “there is no reason why a person of ordinary skill in the art would begin with the teachings of the primary reference Mansur and then modify the described hollow fiber ultrafiltration membranes to include chitosan or an anticoagulant. The Examiner simply argues that since the membranes of the various references are "similar" that a skilled person would have a reasonable expectation of success to modify the structures. This is not sufficient to uphold a prima facie case of obviousness.” However, Applicants’ argument summarily ignores the detailed rejection of the claims as previous and above. 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, briefly summarized, Mansur discloses a process for preparing a porous hollow fiber polysulfone ultrafiltration membrane for hemodialysis (i.e. blood filtration), and is concerned with increasing hydrophily and avoiding fouling (Abstract), Parham is directed to similar polysulfone blood filtration membranes and is cited to motivate using 8-35 wt% PS in the dope solution because this involves the simple substitution of known PS concentrations used in hollow fiber dope solutions for forming hollow fiber membrane used in the biomedical applications to obtain the predictable result of forming a successful hollow fiber; Kumar is directed to similar polysulfone ultrafiltration membranes and increasing hydrophilicity, and motivates including chitosan in the polymer dope solution in an amount which results in 2.5-5 wt% chitosan with regard to polysulfone in the final membrane and drying the membrane after washing it as disclosed by Kumar because including chitosan in similar polysulfone membranes results in improved biocompatibility and antifouling of the membrane, and because it known to dry similar membranes after formation before used and/or storage; Otto is directed to similar polysulfone ultrafiltration membranes used for blood filtration and motivates grafting a coating of the anticoagulant heparin on the hollow fiber membranes inner and/or outer surface as disclosed by Otto in order to improve the hemocompatibility of the membrane when used with blood and because it “serves the function of removal of toxins of biological and chemical synthetic origin, their metabolites and degradation products of blood, blood substitutes or solutions for the introduction into the human and/or animal blood circulation” [0083].
Thus each reference is analogous art, being related to similar membranes used for similar purposes and to solve similar goals, and each provides proper motivation to modify the primary invention of Mansur, and the claims remain rejected.
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.
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/ERIC J MCCULLOUGH/ Examiner, Art Unit 1773
/BENJAMIN L LEBRON/ Supervisory Patent Examiner, Art Unit 1773