Prosecution Insights
Last updated: April 19, 2026
Application No. 18/495,033

DISSOLUTION OF CHITOSAN IN APROTIC AQUEOUS MEDIUM COMPOSITION, PREPARATION METHODS AND BIOMEDICAL USES THEREOF

Non-Final OA §103
Filed
Oct 26, 2023
Examiner
KRISHNAN, GANAPATHY
Art Unit
1693
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Oligo Médic Inc.
OA Round
1 (Non-Final)
52%
Grant Probability
Moderate
1-2
OA Rounds
3y 4m
To Grant
53%
With Interview

Examiner Intelligence

Grants 52% of resolved cases
52%
Career Allow Rate
566 granted / 1087 resolved
-7.9% vs TC avg
Minimal +0% lift
Without
With
+0.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
63 currently pending
Career history
1150
Total Applications
across all art units

Statute-Specific Performance

§101
2.9%
-37.1% vs TC avg
§103
38.4%
-1.6% vs TC avg
§102
16.8%
-23.2% vs TC avg
§112
23.6%
-16.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1087 resolved cases

Office Action

§103
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 . Claims 1-2, 4-8, 10-11, 14-23 and 25 are pending in the application. Claims 3, 9, 12-13 and 24 have been canceled. Preliminary amendment filed 10/26/2023. Priority This application is a 371 of PCT/CA2022/050626 filed 04/25/2022. This application claims the benefit of 63182187 filed 04/30/2021. The parent application 63182187 to which priority is claimed is seen to provide adequate support under 35 U.S.C. 112 for claims 1-2, 4-8, 10-11, 14-23 and 25 of this application. Drawings The drawings are objected to because Figure 5 is fuzzy. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance. Claim Objections Claim 15 is objected to because of the following informalities: In claim 15 the recitation ‘cross-likers’ should be replaced by the recitation ‘cross-linkers’. The term ‘mixtures’ should be replaced by the term ‘solutions’. The term ‘functions’ should be replaced by ‘functional groups’. Appropriate correction is required. Applicant is requested to check the specification for support for the said recitations. 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, 4-6, 8, 10-11, 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) in view of Muzzarelli et al (Carbohydrate Research, 1982, 107, 199-214) and further in view of Anderson (WO 2009/056602 A1), Hou et al (CN 111363063 A, Machine English Translation, pages 1-2) and Nie et al (Scientific Reports, 25 October, 2016, 1-8). One of the embodiments of Selmani is a method of preparing a composition comprising dissolving a polyglucosamine in a solution of glycoxylate at a pH between 7 and 8 in water (page 3, para 0009; page 6, para 0040, 0044; page 12, para 0061; 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 a 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 of 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, 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). 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to GANAPATHY KRISHNAN whose telephone number is (571)272-0654. The examiner can normally be reached M-F 8.30am-5pm. 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, Scarlett Goon can be reached at 571-270-5241. 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. /GANAPATHY KRISHNAN/Primary Examiner, Art Unit 1693
Read full office action

Prosecution Timeline

Oct 26, 2023
Application Filed
Feb 17, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12600742
MARKERS, CONJUGATES, COMPOSITIONS AND METHODS FOR HYPOXIA IMAGING, MAPPING, AND THERAPY
2y 5m to grant Granted Apr 14, 2026
Patent 12594296
METHODS FOR TREATMENT OR PREVENTION OF DAMAGE RESULTING FROM RADIATION, TRAUMA OR SHOCK
2y 5m to grant Granted Apr 07, 2026
Patent 12589108
Injectable bifunctional hydrogel with antibacterial activity as well as the preparative method and the use thereof
2y 5m to grant Granted Mar 31, 2026
Patent 12590306
PROCESSES FOR PREPARING PHOSPHORODIAMIDATE MORPHOLINO OLIGOMERS VIA FAST-FLOW SYNTHESIS
2y 5m to grant Granted Mar 31, 2026
Patent 12582148
Compositions and Methods for Improving Quality of Life in Patients with Autism Spectrum Disorder
2y 5m to grant Granted Mar 24, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

1-2
Expected OA Rounds
52%
Grant Probability
53%
With Interview (+0.5%)
3y 4m
Median Time to Grant
Low
PTA Risk
Based on 1087 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month