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 .
The amendment filed 22 June 2026 has been received, entered and considered. The following information has been made of record in the instant amendment:
1. Claims 3, 9, 12-13, 24 and 26 have been canceled. The said claims were canceled in a preliminary amendment.
2. No new Claims have been added.
3. Claim 15 has been amended.
4. Remarks drawn to drawings, claim objections, and rejection under 35 USC 103.
The following objection(s)/rejection(s) has/have been overcome:
5. The objection to Fig. 5 being fuzzy has been overcome. Applicant has provided a clear Fig. 5.
6. The objection to claim 15 has been overcome by amendments.
Claims 1-2, 4-8, 10-11, 14-23 and 25 are pending in the case.
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.
Claim(s) 1-2, 4-8, 10-11,14-23, and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Selmani et al (WO2015/013821 A1; cited in IDS filed 10/26/2023; of record) in view of Muzzarelli et al (Carbohydrate Research, 1982, 107, 199-214; of record) and further in view of Anderson (WO 2009/056602 A1; of record), Hou et al (CN 111363063 A, Machine English Translation, pages 1-2; of record) and Nie et al (Scientific Reports, 25 October, 2016, 1-8; of record).
One of the embodiments of Selmani is a method of preparing a composition comprising dissolving polyglucosamine in a solution of glyoxylate at a pH between 7 and 8 in water (page 3, para 0009; page 6, para 0040, 0044; page 12, para 0062; Method of claim 1 and charged aldehyde-glyoxylate; pH as in claim 2). The polyglucosamine can be chitosan (page 8, para 0048; chitosan as in claim 1). The amine groups of the chitosan will form an imine bond as shown in the reaction scheme at para 0044 (as in claim 1). Since sodium salt of glyoxylate is used it is a charged aldehyde salt solution as in claims 1 and 4-6. This also reads on the limitation of claim 8. Even though Selamni does not expressly teach all the aldehyde salt solutions as in claims 5-6 and 10, one of ordinary skill in the art will find it obvious to use all of the aldehyde salt solutions recited in claims 5-6 and 10 to dissolve the chitosan and form an imine with a reasonable expectation of success.
Selmani et al does not teach the limitations of claims 7, 11, 14-23 and 25.
Muzzarelli et al drawn to product obtained from chitosan and glyoxylate, teaches the formation of a chitosan imine with glyoxylate and reducing it with sodium cyanoborohydride to get the corresponding carboxymethyl chitosan (page 201, third full para through page 202, part (d). This same reduction of imine can be carried out by the artisan using sodium borohydride for obtaining chitosan-N-ethyl phosphate as in claim 11 and the N-ethyltrimethylammonium chitosan as in claim 25.
Anderson teaches crosslinking of chitosan composition (page 18, lines 27-34). Even though Anderson does not expressly teach that the chitosan composition is not one which obtained by the method of instant claim 1, one of ordinary skill in the art will recognize that the crosslinking the instant composition can also be done as in claim 7. The crosslinking of chitosan produces hydrogels (page 18, lines 31-33). In a similar manner the chitosan solutions as in claims 14 and 15 can be transformed into hydrogels. The crosslinking agents that can be used are bifunctional crosslinkers like squaric acid, diepoxides, 1,4-butanediol diglycidylether, etc. (page 21, lines 1-11; limitations as in claims 14-17). This teaching also renders obvious the use of the other bifunctional reagents as in claims 15, 17 and 18.
Hou et al teaches conversion of chitosan to hydroxyethyl chitosan by first adding sodium hydroxide to chitosan and then reacting the alkali chitosan with 2-chloroethanol, and then acidifying it with HCl to get hydroxyethyl chitosan (page 2-Description). In this process, the hydroxide added removes the H from the OH of the chitosan to give the alkalized chitosan which then reacts with the 2-chloroethanol to give the hydroxyethyl derivative. This same reaction can be performed using LiOH instead of NaOH and chloroethanol on chitosan-GNa to generate the alkaline solution as in claim 19, which can then react with chloroethanol to give the O-hydroxyethylchitosan-GNa solution as in claim 20. The O-hydroxyethylchitosan-GNa solution can then be acidified to produce O-hydroxyethylchitosan and GNa as in claim 21.
Nie et al teaches preparation of chitosan hydrogels with multivalent cations like Cu2+ and Ca2+ (page 7, first two full paras; part of the limitations of claims 22 and 23). This same method can be used to further transform the solutions recited in claim 22 into hydrogels.
MPEP 2141 states, "The key to supporting any rejection under 35 U.S.C. 103 is the clear articulation of the reason(s) why the claimed invention would have been obvious. The Supreme Court in KSR noted that the analysis supporting a rejection under 35 U.S.C. 103 should be made explicit. The Court quoting In re Kahn, 441 F.3d 977, 988, 78 USPQ2d 1329, 1336 (Fed. Cir. 2006), stated that "[R]ejections on obviousness cannot be sustained by mere conclusatory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness.'" KSR, 550 U.S. at, 82 USPQ2d at 1396. Exemplary rationales that may support a conclusion of obviousness include: (A) Combining prior art elements according to known methods to yield predictable results; (B) Simple substitution of one known element for another to obtain predictable results; (C) Use of known technique to improve similar devices (methods, or products) in the same way; (D) Applying a known technique to a known device (method, or product) ready for improvement to yield predictable results; (E) " Obvious to try " choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success; (F) Known work in one field of endeavor may prompt variations of it for use in either the same field or a different one based on design incentives or other market forces if the variations are predictable to one of ordinary skill in the art; (G) Some teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art reference or to combine prior art reference teachings to arrive at the claimed invention."
According to the rationale discussed in KSR above, the rationale in (A) and (B) above are seen to be applicable here since based on the prior art teachings, chitosan has been solubilized in an acid free aqueous solution of charged aldehydes. Analogous solutions are known in the art to be transformed into hydrogels including via crosslinking and using multivalent metal ions. Thus, it is obvious to arrive at the claimed methods in view of the combined teachings of the prior art.
Thus, the claimed invention as a whole would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention over the combined teachings of the prior art. One of ordinary skill in the art will use the claimed method, also taught by the prior art, since dissolution can be done at physiological pH without the need for an acidic environment and without causing precipitation (Selmani, para 0008).
Response to Applicant’s Remarks
Applicant has traversed the rejection of the pending claims under 35 USC 103 of record arguing that Selmani exclusively dissolves glyoxylate as a single aldehyde for dissolving polyglucosamine. It contains no teaching, suggestion or motivation to employ other charged aldehydes such as glycoaldehyde phosphate, glycoaldehyde phosphocholine, carboxybenzaldehyde or aldehyde betaine chloride. The pending application demonstrates that a wide variety of organic salts bearing both an aldehyde function and an ionized group can dissolve chitosan without acid.
Selamni teaches transformation of chitosan dispersion in aqueous solution of glyoxalate mixed without causing precipitation forming a gel-like substance. Nowhere is it taught a method and composition of chitosan, where chitosan is dissolved in aqueous media in the absence of protonating agent, resulting in a solution having a pH around 8 that is not gel-like. Contrary to Selmani, the method provided and claimed herein allows producing acid free chitosan solutions not restricted to gel-like compositions. Fig. 1a displays the rheological graphics evidencing liquid solutions (Fig. 1a) and the gel-like solution is shown in Fig. 1b.
There is no reason a person of ordinary skill would have been motivated to try other charged aldehydes based on Selmani which identifies glyoxylate as uniquely suitable through its interaction with amino groups. The reference gives no broader principle applicable to phosphate-bearing, quaternary ammonium bearing or zwitterionic aldehydes. The breadth of charged aldehydes as in claim 1 is an inventive generalization with no basis in the prior art.
Muzzarelli discloses a process to synthesize N-carboxymethyl chitosan using glyoxalic acid to dissolve chitosan followed by a reduction with sodium borohydride at a pH of between 4 and 6.3, wherein chitosan remains in solution when the pH is increased to 12 and that at neutral pH it is insoluble. Muzzarelli or even any further reference cited does not compensate for the deficiency of Selmani. For these reasons withdrawal of the rejection is requested. (Remarks-page 6).
Applicants’ arguments are not persuasive. Selmani teaches dissolution of chitosan in an aqueous solution of sodium glyoxylate salt, which is a charged aldehyde/salt. Based on this teaching there is a suggestion that other similar charged aldehydes can be used for dissolving chitosan. In Example 1, at para 0062 there is no acid present. The pH is also at 7 to 8. Selmani teaches that after mixing the two components a gel-like solution is obtained. In Example II at para 0076 in the instant specification chitosan is suspended in a glyoxylate solution having a pH of around 7. The glyoxylate used is sodium salt as defined at para 0051 in the specification.
When the prior art teaches a method of dissolving chitosan in an acid free solution of charged aldehyde using the same method steps as in the instant case it is not clear what is done differently that produces an acid free chitosan composition that is distinct from that of Selmani. Applicant refers to Figures 1a and 1B which display the rheological graphics evidencing liquid solutions (Fig. 1a) and the gel-like solution is shown in Fig. 1b. However, the description of the drawings at para 0042 in the instant specification teaches that the rheological measurement recorded is for chitosan-GAP gel-like solution, which is different from the prior art product.
Muzzarelli may teach the use of glyoxylic acid to dissolve chitosan followed by reduction with NaBH3. However, just like in Muzzarelli, the chitosan in Selmani (and the instant case) forms an imine bond with the charged aldehyde, which can be reduced using sodium borohydride. Selmani’s composition is aqueous and there is no acid present. It is a gel-like solution as in the instant case. The pH of the solution is around 7 to 8. The pH can be adjusted to an appropriate value for the reduction step if needed after obtaining the chitosan solution. Therefore, the same reduction of the imine bond can be done. Applicant has also done the same with chitosan-betaine aldehyde solution (para 0084 in the specification).
Anderson, Hou and Nie teach the limitations, which, like Muzzarelli, can be used as in claims 7, and 14-23.
The combined teachings of the cited prior art render the instant claims obvious. The rejection is maintained.
Conclusion
1. Pending Claims 1-2, 4-8, 10-11, 14-23 and 25 are rejected.
2. Claims 3, 9, 12-13, 24 and 26 have been canceled.
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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/GANAPATHY KRISHNAN/Primary Examiner, Art Unit 1693
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