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 .
DETAILED ACTION
Claims 3-4 are cancelled. Claims 1-2 and 5-13 are pending. Claims 9-13 are withdrawn. Claims 1-2 and 5-8 are under examination.
The rejection of claims 1-3 and 6-7 under 35 U.S.C. §102(a)(1) and 102(a)(2) as being anticipated by Grubbs et al. is withdrawn in light of the cancellation of claim 3 and the amendment to claim 1 requiring an alkali solution comprising a carboxyl-group containing compound comprising citric acid, which Grubbs does not teach.
Priority
This application is a 371 of PCT/KR2021/002029 filed 2/17/2021, which claims benefit of REPUBLIC OF KOREA 10-2020-0019067 filed 2/17/2020.
Claim Rejections - 35 USC § 103
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 1-2 and 5-7 are rejected under 35 U.S.C. 103 as being unpatentable over Grubbs et al. (US 2016/0263554 A1, published September 15, 2016; previously cited) in view of Abdouss et al. (“Citric acid-modified acrylic micro and nanofibers for removal of heavy metal ions from aqueous media”, Desalination and Water Treatment, 2014, Volume 52, Issue 37-39, pp.7133-7142; previously cited) and Stone et al. (“In situ citric acid crosslinking of alginate/polyvinylalcohol electrospun nanofibers”, Materials Letters, 2013, Volume 112, pp.32-35).
Regarding claim 1, Grubbs teaches membranes including polysaccharide fibers (abstract). Grubbs teaches the fibers can be fabricated using electro-spinning, electro-blowing, blowing-assisted electro-spinning, and/or solution blowing technologies (description p.4, [0066]). Grubbs further teaches contacting ultra-fine polysaccharide nanofibers with an oxidation agent to form an activated polysaccharide nanofiber possessing functional groups selected from carboxylates (description p.17, claim 10). Grubbs teaches oxidized cellulose nanofibers were produced by preparing cellulose in water with sodium bromide and TEMPO in the same mixture; sodium hypochlorite solution was added and the pH value was kept at about 10.5-11 (monitored with a pH meter) (description p.6, [0078]). Grubbs teaches the oxidation reaction broke up the cellulose wood pulp into smaller fibers and only the surface primary hydroxyl groups of the fiber were oxidized to carboxylates (description p.6, [0080]). Grubbs further teaches determining the amount of carboxylate groups on the modified CNF (m-CNF) (description p.6, [0080]-[0082]).
Grubbs does not teach an alkali solution of at least pH 12.0. However, Grubbs teaches that the pH value of the sodium hypochlorite solution was maintained at 10.5-11. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the pH of the sodium hypochlorite solution to pH 12.0 to arrive at the claimed condition, because it was known in the art at the time of invention that the pH of the alkaline solution can be adjusted to the desired pH and monitored using a pH meter as taught by Grubbs.
Grubbs does not teach 2-2) treating the surface of the fiber assembly treated with the alkali solution with a solution comprising: a) a carboxyl-group containing compound comprising citric acid and b) an aqueous solution of an alcohol having 3 to 10 carbon atoms as a solvent.
However, Abdouss teaches citric acid-modified acrylic micro and nanofibers for removal of heavy metal ions from aqueous media (title). Abdouss teaches that citric acid was grated to carboxylic acid groups to increase the density of carboxyl groups on the fibers surface (abstract). Abdouss teaches polyacrylonitrile fibers (HPAN) have desirable characteristics, such as high chemical resistance, mechanical properties, and thermal stability besides low flammability (p.7134, 1st column 1st full paragraph). Abdouss further teaches that polyacrylonitrile fiber with an abundance of nitrile groups that can be easily transformed into various functional groups (carboxyl etc.) is one of the most suitable materials for the preparation of chelating fibers (p.7134, 1st column 1st full paragraph).
Abdouss teaches that PAN fibers were hydrolyzed by adding 3 g of fiber to a flask containing 100mL of ethanol/water solution and 10% (w/v) NaOH; reacted with DCC to activate the carboxylic groups of HPAN fibers, and then reacted with citric acid in a mixture of THF and dioxane (50:50 v/v) at 45°C for 180 minutes (p.7134, 2nd column 2.2.1. Alkaline hydrolysis of PAN; 2.2.2. Reaction with citric acid).
Stone teaches preparing 2 wt% of alginate solution of DI water and 2-propanol and 10 wt% of PVA solutions; then adding 5 wt% solid citric acid followed by constant stirring (i.e. a carboxyl group-containing compound comprising citric acid and an alcohol having 3 carbon atoms) (p.33, 1st column Experimental section – preparation of electrospinning solution).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the sodium hypochlorite solution taught by Grubbs with a solution comprising citric acid and 2-propanol taught by Stone and add polyacrylonitrile fibers taught by Abdouss, because Abdouss teaches a citric acid solution and polyacrylonitrile fiber with an abundance of nitrile groups that can be easily transformed into various functional groups (carboxyl etc.) is one of the most suitable materials for the preparation of chelating fibers. One of ordinary skill in the art would have found it beneficial to use an agent that contained multiple carboxyl groups to further increase the availability of carboxyl groups present on the fibers in order to increase the number of carboxyl binding sites available to bind a bio-substance.
Regarding claim 2, Grubbs teaches the ultra-fine polysaccharide nanofibers include a polysaccharide selected from the group consisting of cellulose, chitin, collagen (description p.17, claim 13).
Regarding claim 5, Grubbs teaches the scaffold layer of the membrane such as polyacrylonitrile may be electrospun on a substrate (description p.5, [0069]).
Regarding claim 6, Grubbs teaches the oxidation agents may be contacted with the nanofibers for a period of time from about 0.5 hours to about 48 hours, at temperatures from about 20°C to about 100°C, and in embodiments from about 50°C to about 80°C (description p.3, [0043]). Grubbs teaches the base may be contacted with the nanofibers for a period of time from about 0.1 hours to about 24 hours, and the base may be contacted at temperatures from about 20°C to about 100°C, and in embodiments from about 50°C to about 80°C (description p.3, [0045]).
Regarding claim 7, Grubbs teaches sodium hypochlorite solution (10-13% aqueous solution) was added to the stirred solution at room temperature (description p.6, [0078]). The 10-13% aqueous solution contains water.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Grubbs et al. (US 2016/0263554 A1) in view of Abdouss et al. (Desalination and Water Treatment, 2014, Volume 52, Issue 37-39, pp.7133-7142) and Stone et al. (Materials Letters, 2013, Volume 112, pp.32-35) as applied to claim 1 above, and further in view of Akbari et al. (Polymer International, 2008, Vol. 57, Issue 6, pp.846-853; previously cited).
The teachings of Grubbs et al., Abdouss et al. and Stone et al. are discussed above.
Regarding claim 8, Grubbs teaches 75.0 grams of sodium hypochlorite, 10-13% aqueous solution was added to the stirred solution at room temperature.
Stone teaches adding 5 wt% of solid citric acid by the total weight of the polymer mixture was added followed by constant stirring for 2 hours (p.33, 1st column Experimental – preparation of electrospinning solution).
Grubbs, Abdouss and Stone does not teach the solution containing the carboxyl group-containing compound contains the compound containing the carboxyl group at a concentration of 8 to 15 M.
However, Akbari teaches reacting poly acrylonitrile/acrylic acid copolymer with citric acid (abstract). Akbari teaches a solution of citric acid (CA) was dissolved and added to the flask where the DCC activated film was placed, with the mole fraction of CA equal to the mole fraction of AA that was equal to 15% of P(AN/AA) (p.849, 1st column 2nd paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the amount of the carboxyl group-containing compound, in the method of Grubbs as modified by Abdouss and Stone, to a desired concentration of 8 to 15M, because Akbari teaches adding an amount of citric acid equal to a mole fraction of AA equal to 15% of P(AN/AA). One of ordinary skill in the art would reasonably expect that modifying the concentration of the carboxyl group-containing compound added to the reaction would predictably result in creating a fiber assembly containing a carboxyl reactive group, because it was known in the art at the time of invention that citric acid could be used to add carboxyl groups to poly acrylonitrile fibers. While the exact concentration is not disclosed by Grubbs, Abdouss, Stone or Akbari, it is generally noted that differences in concentration do not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Response to Arguments
Inventor Su Yeon Lee has submitted a declaration under 37 CFR 1.132 on 10/13/2025. Declaration item 5 identifies that the declarant’s opinion is that one of ordinary skill in the art would not have modified the method of Grubbs in view of Abdouss and Akbari to arrive at the claimed invention. Declaration item 6 argues that the claimed method has a technical advantage that would be unexpected over the cited references, particularly the level of carboxyl group modification and introduction of biosubstances into the fiber assembly. Declaration item 7 identifies differences in biotin binding based on the solvent of citric acid used for modification. Declaration item 8 states that the activation of carboxyl groups changed depending on the solvent used, and the amount of carboxyl groups introduced and activated varied based on the solvent.
The declaration under 37 CFR 1.132 filed on 10/13/2025 is insufficient to overcome the rejection of claims 1-2 and 5-8 under 35 U.S.C. 103 as being unpatentable over Grubbs et al. in view of Abdouss et al. as set forth in the last office action because the declaration does not provide any comparative data suggesting that replacing the hypochlorite solution of Grubbs with the citric acid in THF/dioxane taught by Abdouss would affect the operability of the resulting fiber assembly (Declaration dated 10/13/2025, item 5). One of ordinary skill in the art would reasonably expect that replacing hypochlorite taught by Grubbs with citric acid taught by Abdouss would predictably result in a fiber assembly having a modified surface as required by the claims. Declaration item 6 states that an increased modification to the surface of the fibers does not result in a proportional increase to the biosubstance into the fiber assembly (Declaration dated 10/13/2025, item 6). However, this is not a claim limitation. Declaration items 7, 8 and 9 discuss the differences in using solvents having different carbon atoms, the availability of carboxyl groups for binding the bio-substance, and experimental results of biotin content introduced into the fibers based on the citric acid solvent solution used, and states that one of ordinary skill would not expect the results provided. However, inclusion of carboxyl groups into the fibers is an expected result, as discussed in the rejection above.
Regarding the rejection of claims 4-5: Applicant argues that claim 1 has been amended to incorporate the subject matter of claims 3, 5 and 7 in part and cancelled claims 4-5; further Grubbs does not disclose or suggest the solution containing the carboxyl-containing compound comprises an alcohol having 3 to 10 carbon atoms or an aqueous solution of the alcohol as a solvent, as required by amended claim 1; Abdouss fails to remedy the deficiencies of Grubbs (See Remarks date 10/13/2025, p.8, paragraphs 1-2). Applicant refers to the Declaration submitted 10/13/2025, and reproduces items 6-9, arguing that the technical results of the claimed method would have been unexpected over the cited references because the claimed method results in a higher level of activated carboxyl groups available to bind bio-substances, and one of ordinary skill in the art would not expect such results (See Remarks dated 10/13/2025, p.9 – p.13 first paragraph).
Regarding the rejection of claim 8: Applicant argues that the arguments with respect to claim 5 are incorporated here, and Akbari fails to remedy the deficiencies of Grubbs and Abdouss (See Remarks dated 10/13/2025, p.13 2nd paragraph). Applicant argues that Grubbs and Akbari do not disclose or suggest the solution containing the carboxyl group-containing compound is at a concentration of 8 to 15M (See Remarks dated 10/13/2025, p.13 last paragraph). Applicant argues that Akbari teaches the amount of citric acid is the same as the mole fraction of AA in said polymer, but provides no information on the concentration of citric acid in solution; therefore a prima facie case of obviousness has not been established (See Remarks dated 10/13/2025, p.14 top paragraph). Applicant argues that the office action fails to point to a disclosure in Grubbs or Akbari that would lead one of ordinary skill in the art to select the specifically claimed concentration (See Remarks dated 10/13/2025, p.14 last paragraph). Applicant argues that routine optimization
Applicant's arguments filed October 13, 2025 have been fully considered but they are not persuasive. The features of carboxyl group activation and level of bio-substance binding to the fiber surface are features that are not claimed. The open language “comprising” does not preclude the use of THF-dioxane solvent taught by Abdouss.
Applicant’s argument regarding the level of activation of the carboxyl groups is not persuasive. The Stone reference uses citric acid in a 2-propanol solution. One of ordinary skill in the art would have been motivated to modify the solution based upon Abdouss’ teaching of a citric acid solution and polyacrylonitrile fiber with an abundance of nitrile groups that can be easily transformed into various functional groups (carboxyl etc.), which makes them the most suitable materials for the preparation of chelating fibers. Grubbs teaches fibers can be fabricated using electro-spinning. Grubbs further teaches contacting ultra-fine polysaccharide nanofibers with an oxidation agent to form activated polysaccharide nanofiber possessing functional groups selected from carboxylates. Grubbs teaches adding sodium hypochlorite solution and maintaining a basic pH at about 10.5-11. Abdouss teaches citric acid-modified acrylic fibers. Abdouss further teaches that polyacrylonitrile fiber with an abundance of nitrile groups that can be easily transformed into various functional groups such as carboxyl is one of the most suitable materials for preparing chelating fibers. Abdouss teaches hydrolyzing the fibers using 10% NaOH and then reacting with citric acid. Stone teaches a citric acid solution using 2-propanol. It would have been obvious to one of ordinary skill in the art to modify the method of Grubbs to treat the fibers with citric acid taught by Abdouss using a citric acid-propanol solution taught by Stone to arrive at the claimed invention. One of ordinary skill in the art would reasonably expect that treating the fibers of Grubbs with citric acid would predictably result in a plurality of fibers having a carboxyl group as required by the claimed invention.
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.
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/DEEPA MISHRA/Examiner, Art Unit 1657