FILTER FOR REMOVING SUBSTANCES FROM BLOOD

DETAILED ACTION This action is in response to the RCE with Remarks and Affidavit filed 07/30/2026, in which no claims have been amended, claims 21-23 have been newly added and claims 1, 3-7 and 9-23 are pending and ready for examination. Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 07/30/2026 has been entered. 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, 3-7 and 9-23 are rejected under 35 U.S.C. 103 as being unpatentable over US 2006/0207937 Al (hereinafter “Bonaguidi”) in view of US 2006/0169635 A1 (hereinafter “Zambianchi”). Regarding Claim 1 Bonaguidi discloses a filter medium for removing substances from blood comprising: a porous, polymeric non-woven fabric for removing selected components (leukocytes) from blood and recovering other selected components, said fabric comprising a nonwoven material made of polybutylene terephthalate; and a polymeric coating comprising hydrophobic and hydrophilic monomers (a statistical copolymer of vinyl acetate and vinyl pyrrolidone) applied to said porous, polymeric fabric; Abstract, Ex. 1. wherein said coating comprises an acetonic solution (i.e. a solution comprising acetone) comprising a copolymer of vinyl acetate and vinyl pyrrolidone [0057], [0059], wherein the ratio of vinyl acetate to vinyl pyrrolidone is 7:1; [0057], and wherein the coating solution consists of the polymeric coating material (i.e. the copolymer) and a solvent, where the solvent may be 50-99.5% of the solution, and thus the remainder may be the copolymer, i.e. 0.5-50 wt% of the coating solution [0051], [0053]. Bonaguidi does not disclose said non-woven material having hydrophilic and hydrophobic segments. However Zambianchi further discloses a similar filter medium for removing substances from blood (including leukocytes) wherein the filter comprises a nonwoven fabric (i.e. which is a porous, polymeric fabric) made from polyether-ester copolymer (Abstract, [0022], Ex. 2) which thus comprises hydrophilic (ester) and hydrophobic (ether) segments. Wherein “filter of the invention can be used to advantage in any application relating to filtration of blood and blood components, particularly for the removal of leukocytes” and which may be surface coated or grafted [0040]. Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter medium of Bonaguidi by substituting for the nonwoven for the polyether-ester copolymer nonwoven of Zambianchi because this involves the simple substitution of known nonwovens (which may be surface coated) for use as leukocyte filtration from blood to obtain the predictable result of for a successful leukocyte filter. Thus resulting in a polyether-ester copolymer nonwoven comprising hydrophilic and hydrophobic segments coated in a copolymer of vinyl acetate and vinyl pyrrolidone. Regarding Claim 3 Bonaguidi in view of Zambianchi discloses the filter medium of Claim 1, wherein said porous, polymeric fabric comprises a polymeric structure of: PNG media_image1.png 163 969 media_image1.png Greyscale ; see Zambianchi [0029], supra. Regarding Claim 4 Bonaguidi in view of Zambianchi discloses the filter medium of Claim 1, wherein said hydrophobic segments include repeating units derived from an alkylene glycol and at least one aromatic dicarboxylic acid or ester; (resulting polymer has a backbone built up of a hard segment (hydrophobic) of repeating units, derived from the alkyleneglycol (preferably 1,4-butandiol) and the aromatic dicarboxylic acid (preferably terephthalic acid or dimethylterephthalate) and a soft hydrophilic segment deriving from one polyalkylene oxide glycol”, Zambianchi [0028] Regarding Claim 5 Bonaguidi in view of Zambianchi discloses the filter medium of Claim 1, wherein said hydrophilic segments derived from at least one polyalkylene oxide glycol; Zambianchi [0028], supra. Regarding Claim 6 Bonaguidi in view of Zambianchi discloses the filter medium of Claim 1, wherein said coating solution is obtained by the polyreaction of a hydrophobic and hydrophilic monomer (Bonaguidi Abstract, [0022]). Regarding Claim 7 Bonaguidi in view of Zambianchi discloses the filter medium of Claim 6, wherein said hydrophobic monomer is vinyl acetate (a vinyl ester Bonaguidi [0029]) and the hydrophilic monomer is vinyl pyrrolidone (a monomer with a basic group Bonaguidi [0033]); Bonaguidi Abstract, Ex. 1. Regarding Claim 9 Bonaguidi in view of Zambianchi discloses the filter medium of Claim 8, wherein the ratio of vinyl acetate to vinyl pyrrolidone is 7:1; Bonaguidi [0057]. Regarding Claim 10 Bonaguidi discloses a blood filter assembly comprising a housing which is used to pass fluid through a filter in the housing (“bag containing the blood to be cleaned, a housing divided by the filter into two chambers, and a further container in which the filtrate is trapped, these parts of the device being connected by hose pipes”, [0054], [0061]) and while not sepficially disclosed the housing must necessarily/inherently comprise an inlet and an outlet , i.e. to allow fluid flow from the bag to the filtrate container through the hose pipes, said filter comprising one or more filter layers (of coated non-woven fabric), including as much as 50 filter layers [0055], [0061], such that when there are at least 3 layers the first layer may be considered a pre- and the last layer a post-filter, and the middle layer the claimed filter medium; even though they are all the same material. Said filter medium comprising: a porous, polymeric non-woven fabric for removing selected components (leukocytes) from blood and recovering other selected components, said fabric comprising a nonwoven material made of polybutylene terephthalate; and a polymeric coating comprising hydrophobic and hydrophilic monomers (a statistical copolymer of vinyl acetate and vinyl pyrrolidone) applied to said porous, polymeric fabric; Abstract, Ex. 1. wherein said coating comprises an acetonic solution (i.e. a solution comprising acetone) comprising a copolymer of vinyl acetate and vinyl pyrrolidone [0057], [0059], wherein the ratio of vinyl acetate to vinyl pyrrolidone is 7:1; [0057], and wherein the coating solution consists of the polymeric coating material (i.e. the copolymer) and a solvent, where the solvent may be 50-99.5% of the solution, and thus the remainder may be the copolymer, i.e. 0.5-50 wt% of the coating solution [0051], [0053]. Bonaguidi does not disclose said non-woven material having hydrophilic and hydrophobic segments. However Zambianchi further discloses a similar filter medium for removing substances from blood (including leukocytes) wherein the filter comprises a nonwoven fabric (i.e. which is a porous, polymeric fabric) made from polyether-ester copolymer (Abstract, [0022], Ex. 2) which thus comprises hydrophilic (ester) and hydrophobic (ether) segments. Wherein “filter of the invention can be used to advantage in any application relating to filtration of blood and blood components, particularly for the removal of leukocytes” and which may be surface coated or grafted [0040]. Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the filter medium of Bonaguidi by substituting for the nonwoven for the polyether-ester copolymer nonwoven of Zambianchi because this involves the simple substitution of known nonwovens (which may be surface coated) for use as leukocyte filtration from blood to obtain the predictable result of for a successful leukocyte filter. Thus resulting in a polyether-ester copolymer nonwoven comprising hydrophilic and hydrophobic segments coated in a copolymer of vinyl acetate and vinyl pyrrolidone. Regarding Claim 11 Bonaguidi in view of Zambianchi discloses the blood filter assembly of Claim 10, wherein said filter medium comprises a stack of a plurality of said filter sheets; Bonaguidi [0055], [0061]. Regarding Claim 12 Bonaguidi in view of Zambianchi discloses a method of making a filter for removing substances from blood comprising: forming a fabric sheet comprising polymer [0017] (where forming the nonwoven is inherent to obtaining said nonwoven); and coating at least one side said fabric sheet with a coating solution comprising a copolymer of vinyl acetate and vinyl pyrrolidone; Abstract, Ex. 1. wherein said coating comprises an acetonic solution (i.e. a solution comprising acetone) comprising a copolymer of vinyl acetate and vinyl pyrrolidone Bonaguidi [0057], [0059]. wherein said coating comprises an acetonic solution (i.e. a solution comprising acetone) comprising a copolymer of vinyl acetate and vinyl pyrrolidone [0057], [0059], wherein the ratio of vinyl acetate to vinyl pyrrolidone is 7:1; [0057], and wherein the coating solution consists of the polymeric coating material (i.e. the copolymer) and a solvent, where the solvent may be 50-99.5% of the solution, and thus the remainder may be the copolymer, i.e. 0.5-50 wt% of the coating solution [0051], [0053]. Bonaguidi does not disclose the fabric sheet comprises polyether-ester copolymer. However Zambianchi further discloses a similar filter medium for removing substances from blood (including leukocytes) wherein the filter comprises a nonwoven fabric (i.e. which is a porous, polymeric fabric) made from polyether-ester copolymer (Abstract, [0022], Ex. 2) which thus comprises hydrophilic (ester) and hydrophobic (ether) segments. Wherein “filter of the invention can be used to advantage in any application relating to filtration of blood and blood components, particularly for the removal of leukocytes” and which may be surface coated or grafted [0040]. Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the method of Bonaguidi by substituting for the nonwoven for the polyether-ester copolymer nonwoven of Zambianchi because this involves the simple substitution of known nonwovens (which may be surface coated) for use as leukocyte filtration from blood to obtain the predictable result of for a successful leukocyte filter. Thus resulting in a polyether-ester copolymer nonwoven comprising hydrophilic and hydrophobic segments coated in a copolymer of vinyl acetate and vinyl pyrrolidone. Regarding Claim 13 Bonaguidi in view of Zambianchi discloses the method of Claim 12, wherein said coating comprises immersing (i.e. dipping) said fabric in a bath of said coating solution; Bonaguidi [0059], Ex. 1 Regarding Claim 14 Bonaguidi in view of Zambianchi discloses the method of Claim 13, further comprising removing excess coating solution from fabric sheet (“excess solution was dripped”, Bonaguidi [0060]. Regarding Claim 15 Bonaguidi in view of Zambianchi discloses the method of Claim 12, further comprising drying said coated fabric sheet at a temperature of 95°C, Bonaguidi [0060]. Regarding Claim 16 Bonaguidi in view of Zambianchi discloses the method of Claim 12, comprising forming said fabric from melt-blown fibers made of said polyether-ester copolymer; Zambianchi [0050]. Regarding Claim 17 Bonaguidi in view of Zambianchi discloses the filter assembly of Claim 10, wherein the porous, polymeric fabric comprises a polyester-ester copolymer, Zambianchi Abstract, [0022], Ex. 2, supra. Regarding Claim 18 Bonaguidi in view of Zambianchi discloses the filter assembly of Claim 10, wherein the porous, polymeric fabric comprises a polymeric structure of: PNG media_image1.png 163 969 media_image1.png Greyscale ; see Zambianchi [0029], supra. Regarding Claim 19 Bonaguidi in view of Zambianchi discloses the filter assembly of Claim 10, wherein said hydrophobic segments include repeating units derived from an alkylene glycol and at least one aromatic dicarboxylic acid or ester; (resulting polymer has a backbone built up of a hard segment (hydrophobic) of repeating units, derived from the alkyleneglycol (preferably 1,4-butandiol) and the aromatic dicarboxylic acid (preferably terephthalic acid or dimethylterephthalate) and a soft hydrophilic segment deriving from one polyalkylene oxide glycol”, Zambianchi [0028]. Regarding Claim 20 Bonaguidi in view of Zambianchi discloses the filter assembly of Claim 10, wherein said hydrophilic segments derived from at least one polyalkylene oxide glycol; Zambianchi [0028], supra. Regarding Claim 21 Bonaguidi in view of Zambianchi discloses the filter medium of Claim 1, wherein it is disclosed in Bonaguidi that the filter medium provided a platelet recovery of 70-80% (Table 1) and a residual white blood cell concentration of 0.5-0.8 X 10⁶ per 500 ml of whole blood, which overlap the ranges claimed, and where Zambianchi discloses that in comparison to PBT the polyester copolymer (PEC) increases the ability of the filter material to remove leukocytes (to 0.2-0.5 X 10⁶) while also providing increased platelet recovery; and thus the combination of the coating of Bonaguidi with the PEC of Zambianchi instead of PBT would similarly be expected to provide increased removal of leukocytes while also providing increased platelet recovery; and as such one of skill in the art would be motivated to provide a filter having at least the platelet recovery and residual white blood cell concentrations as disclosed in Bonaguidi as well as further increased removal of leukocytes and increased platelet recovery, i.e. overlapping the ranges claimed. 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). Regarding Claim 22 Bonaguidi in view of Zambianchi discloses the blood filter assembly of Claim 10, wherein it is disclosed in Bonaguidi that the filter medium provided a platelet recovery of 70-80% (Table 1) and is configured to yield a residual white blood cell concentration of 0.5-0.8 X 10⁶ per 500 ml of whole blood, which overlap the ranges claimed, and where Zambianchi discloses that in comparison to PBT the polyester copolymer (PEC) increases the ability of the filter material to remove leukocytes (to 0.2-0.5 X 10⁶) while also providing increased platelet recovery; and thus the combination of the coating of Bonaguidi with the PEC of Zambianchi instead of PBT would similarly be expected to provide increased removal of leukocytes while also providing increased platelet recovery; and as such one of skill in the art would be motivated to provide a filter having at least the platelet recovery and configured to yield residual white blood cell concentrations as disclosed in Bonaguidi as well as further increased removal of leukocytes and increased platelet recovery, i.e. overlapping the ranges claimed. 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). Regarding Claim 23 Bonaguidi in view of Zambianchi discloses the method of Claim 12, wherein it is disclosed in Bonaguidi that the filter medium provided a platelet recovery of 70-80% (Table 1) and is configured to yield a residual white blood cell concentration of 0.5-0.8 X 10⁶ per 500 ml of whole blood, which overlap the ranges claimed, and where Zambianchi discloses that in comparison to PBT the polyester copolymer (PEC) increases the ability of the filter material to remove leukocytes (to 0.2-0.5 X 10⁶) while also providing increased platelet recovery; and thus the combination of the coating of Bonaguidi with the PEC of Zambianchi instead of PBT would similarly be expected to provide increased removal of leukocytes while also providing increased platelet recovery; and as such one of skill in the art would be motivated to provide a filter having at least the platelet recovery and configured to yield residual white blood cell concentrations as disclosed in Bonaguidi as well as further increased removal of leukocytes and increased platelet recovery, i.e. overlapping the ranges claimed. 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). Response to Arguments Applicant's arguments filed 07/30/2026, and the Declaration of Paolo Bonaguidi under 37 C.F.R. 1.132, have been fully considered but they are not persuasive. In response to Applicants’ argument that Zambianchi does not provide a teaching toward a 2 wt% VA/VP coating solution and that one of ordinary skill in the art would not have been motivated to use Zambianchi’s PEC with the coating of Bonaguidi; the Examiner disagrees. While Zambianchi does not disclose specifically using 2 wt% VA/VP coating solution, Bonaguidi does disclose specifically using a 4 wt% VA/VP coating solution in the examples, and further disclose the coating solution may be 50-99.5% solvent, and thus the remainder may be the copolymer, i.e. 0.5-50 wt% of the coating solution [0051], [0053], and even further disclose that the amount of coating polymer is adjusted based on the properties of the specific substrate and specific coating polymer, and that it effects the critical surface wetting of the formed filter media. Thus one of skill in the art is clearly taught toward adjusting the coating solution concentrations, including to 2 wt%; the prior art need not disclose the exact percent as claimed to be obvious. Nothing in Zambianchi teaches away from this. The only evidence provided by Applicants that one of skill in the art would not have made the substitution is from the Declaration of Mr. Bonaguidi, with regard to the Declaration, the statements of one of the inventors of the Application is not sufficient evidence to establish the knowledge of one of ordinary skill in the art. Where it is further noted that even Applicants’ acknowledge Mr. Bonaguidi may be more than one of ordinary skill in the art. The prior art specifically teaches to adjust the amount of coating to suit the substrate, and thus it is clearly obvious to do so. In response to Applicants’ argument that one of ordinary skill in the art would not have been motivated to apply the coating of the Bonaguidi reference to the PEC substrate of Zambianchi because a relative negative effect on leukocyte removal would be expected; the Examiner disagrees. The evidence for this argument appears to come entirely from the Declaration, as neither reference suggests that a hydrophilic coating on the PEC of Zambianchi would have a negative effect on leukocyte removal, and Zambianchi specifically teaches adding a hydrophilic coating [0040] and thus clearly one would not be dissuaded from doing so. With regard to the Declaration, the statements of one of the inventors of the Application is not sufficient evidence to establish the knowledge of one of ordinary skill in the art. Where it is further noted that even Applicants’ acknowledge Mr. Bonaguidi may be more than one of ordinary skill in the art. In response to Applicants’ argument that the claimed invention provides unexpected results; the Examiner disagrees. Applicants’ argue that “despite expecting reduced leukocyte removal, the combination of the PEC filter and 2 wt% VA/VP coating unexpectedly maintained acceptable leukocyte removal” and produced low water extractables. However, the data provided in the instant disclosure are not sufficient to show unexpected results of the claimed invention. Specifically: 1. There is no evidence provided from the prior art that establishes the results obtained were unexpected. The only evidence supporting Applicants’ argument is the declaration of Mr. Bonaguidi, which is not a substitute for factual evidence, at least because he may have more than ordinary skill in the art and is a named inventor. Further, the results obtained do not appear unexpected from the prior art. It is disclosed in Bonaguidi that the filter medium provided a platelet recovery of 70-80% (Table 1) and a residual white blood cell concentration of 0.5-0.8 X 10⁶ per 500 ml of whole blood, and where Zambianchi discloses that in comparison to PBT the polyester copolymer (PEC) increases the ability of the filter material to remove leukocytes (to 0.2-0.5 X 10⁶) while also providing increased platelet recovery; and thus the combination of the coating of Bonaguidi with the PEC of Zambianchi instead of PBT would similarly be expected to provide increased removal of leukocytes while also providing increased platelet recovery; and as such one of skill in the art would be motivated to provide a filter having at least the platelet recovery and residual white blood cell concentrations as disclosed in Bonaguidi as well as further increased removal of leukocytes and increased platelet recovery. It is also noted that the filtration time using the PEC in Zambianchi was shorter than the PBT media, and thus shorter filtration time would also be expected. And with regard to low water extractables, by Applicants’ rationale, this would have been inherent to any coating with lower polymer amount, and thus not unexpected. 2. Further, Applicant’s provide only one control example (PBT coated with 0.22% VA/VP) and one example of the media as claimed (PEC with 2 wt% VA/VP); and thus Applicants have failed to show the results occur over the entire claimed range because they do not show a sufficient number of tests both inside and outside the claimed range; for example, Applicant’s do not test any coating except 2% VA/VP on PEC, and thus there is no evidence that this wt% is critical, it is fact does not even compare it to a PBT with the same wt%. 3. Further still, as rejected claim 1 is significantly broader than examples in specification, which applicant cites as an example of unexpected results and which are limited to using a PEC substate, where the specific PEC used in not disclosed. The results do not demonstrate that the effects would apply to the broad range of PECs encompassed by claim 1 and thus the evidentiary showing is far from being commensurate in scope with the degree of patent protection sought. Thus the claimed invention is not seen to possess unexpected results and is obvious in view of the cited art. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Eric J. McCullough whose telephone number is (571)272-8885. The examiner can normally be reached Monday-Friday 10:00-6:00. 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, Benjamin L Lebron can be reached at 571-272-0475. 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. /ERIC J MCCULLOUGH/ Examiner, Art Unit 1773 /BENJAMIN L LEBRON/ Supervisory Patent Examiner, Art Unit 1773