DETAILED ACTION
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 .
Change of Examiner
The examiner assigned to this case has changed since the previous office correspondence. Examiner Toriana Vigil will now be examining this application. Contact information can be found at the end of this document.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on December 6, 2024, is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
The information disclosure statement filed May 2, 2025, fails to comply with the provisions of 37 CFR 1.98(a)(4) because it lacks the appropriate size fee assertion. It has been placed in the application file, but the information referred to therein has not been considered as to the merits.
Election/Restrictions
Applicant’s election with traverse of Group 1, claims 1 – 11, in the reply filed on June 16, 2026, is acknowledged.
The traversal is on the ground that the special technical feature identified by the Examiner in the Restriction Requirement dated April 16, 2026, does not account for the limitation that the claimed chitosan-containing vector must comprise 5 to 55% DIPEA (Remarks page 5). This is not found persuasive because the claims of Group 2 do not require 5 to 55% DIPEA. As such, the recitation for 5 to 55% DIPEA is an additional limitation to the single general inventive concept, or same special technical feature, of Groups 1 and 2 (a chitosan-containing vector as set forth in formula I).
In arguendo, if the limitation for 5 to 55% DIPEA was considered a special technical feature of Group 1, then Groups 1 and 2 would lack unity of invention because the groups do not share the same or corresponding technical feature (Group 2 does not recite a requirement for 5 to 55% DIPEA) according to PCT Rule 13.2 (MPEP 1850(ii)).
The restriction requirement is still deemed proper and is therefore made FINAL.
Claim Status
Claims 1 – 14 are pending.
Claims 12 – 14 are withdrawn.
Claims 1 – 11 are examined here-in.
Claim Objections
Various informalities appear throughout the claim set and Applicant is requested to carefully review and revise the claims as appropriate. The specific instances highlighted below are merely exemplary and should be taken to represent a comprehensive list.
Claims 1 – 11 are objected to because of the following informalities:
In claim 1, R8 is followed by an equal sign “=” which is inconsistent with the other R groups defined in the claim and appears to be a typographical error.
In claim 1, “R10” does not have the “10” as subscript which is inconsistent with the other R groups defined in the claim and appears to be a typographical error.
In claim 1, “Alkyl” is capitalized in the phrase “(C8-C12)Alkyl”. “Alkyl” should not be capitalized.
Claim 1 recites the limitation "and up 5% for pegylated units” which likely should be “and up to 5% for pegylated units”.
In line 3 of claim 2, “Chitosan” is capitalized. This is inconsistent with the previous two appearances of the term “chitosan” in the claim. Chitosan is not a proper noun and should not be capitalized in line 3.
In claims 3 and 6 there should be a space between number and units, for example “10kDa” should be “10 kDa”.
Claim 11 refers to “the nanoparticle of claim 9” which appears to be a typographical error and should be “the nanoparticle of claim 10”.
In claim 11, “interference RNA (siRNA)” should be “small interference RNA (siRNA)”.
Again, the aforementioned are examples of informalities throughout the claim set and are not a comprehensive list. Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claim 1 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 1 recites the limitation "and up 5% for pegylated units". There is insufficient antecedent basis for this limitation in the claim because PEG or pegylated units are not previously set out in the claim and it is unclear if this reference is to pendant PEG groups, or if PEG is necessary in the chitosan backbone, or some other scenario.
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 non-obviousness.
Claims 1 – 11 are rejected under 35 U.S.C. 103 as being unpatentable over Fernandes (US 2006/0105049 A1) in view of Jones (US 2016/0362523 A1).
Fernandes teaches nanoparticles comprising folic acid and chitosan for drug delivery (abstract).
Fernandes teaches that chitosan is an attractive polysaccharide for non-viral drug delivery because it has low immunogenicity, minimal toxicity, good biocompatibility, and good biodegradability (paragraphs 0005 – 0007).
Fernandes teaches that inclusion of folic acid in the drug delivery system helps to target the delivery because folic acid binds specifically to its receptor, which may be overexpressed in certain diseases (paragraph 0017).
Fernandes teaches that the folic acid – chitosan conjugate should have a molecular weight between 5 to 600 kDa and a degree of deacetylation from 70 to 95%, with folic acid conjugation in an amount of 2 to 15 mole % per glucosamine residues (paragraph 0025).
Fernandes does not teach diisopropylethylamine covalently linked to chitosan.
Jones teaches the missing element of Fernandes.
Jones teaches graft co-polymers for peptide and protein binding to provide stability and elevated levels in the blood, with an extended half-life, after administration (abstract, paragraphs 0001 – 0002).
Jones teaches the backbone polymer should have free primary amino groups in an amount of W (paragraphs 0018, 0031). Jones teaches adding DIPEA in an amount of 0.5 – 6 x W (paragraphs 0024, 0063). Jones teaches DIPEA is a base where the N atom is shielded by two isopropyl groups and an ethyl group, making it a poor nucleophile (paragraph 0096). The presence of three alkyl groups on the N atom of DIPEA limits the possible reactivity to a single H atom (paragraph 0096). Jones teaches that as a good base and poor nucleophile, DIPEA is a useful organic reagent (paragraph 0096).
Jones teaches conjugation of PEG as a protective side chain that confers hydrophilicity and water-solubility to the polymer backbone (paragraph 0105). Jones teaches PEG has a size range between 2 to 20 kDa (paragraph 0105).
The combination of Fernandes and Jones renders claims 1 – 11 prima facie obvious according to MPEP 2143(i)(g) because a person of ordinary skill in the art would be motivated to modify Fernandes’ teaching for a folic acid chitosan conjugate to include DIPEA as taught by Jones because Jones teaches DIPEA is a good base but poor nucleophile and that DIPEA reactivity with targeted specifically to single H atoms (paragraph 0096). As such, a person of ordinary skill in the art would expect the reaction of DIPEA with a chitosan-containing backbone (as taught by Fernandes) to specifically target groups with an accessible H atom. For the primary amine groups on chitosan, reaction with DIPEA would make these tertiary amines, and they would be expected to have fewer reactions with compounds they may incidentally encounter during drug delivery. The modification of a prior art reference motivated by the teachings or suggestions of another is prima facie obvious according to MPEP 2143(i)(g).
The combination of Fernandes’ teachings for chitosan with a molecular weight of 5 to 600 kDa as a non-viral drug delivery vector (paragraphs 0005 – 0007, 0025) with Jones’ teachings for reacting the primary amino groups of a polymer backbone with DIPEA in an amount of 0.5 – 6 x W (paragraphs 0018, 0024, 0031, 0063) reads on instant claim 1’s recitation for a chitosan-containing vector with 5 to 55% DIPEA and a molecular weight between 10 and 300 kDa.
Fernandes’ teaching for a molecular weight between 5 to 600 kDa overlaps on the instantly claimed range of 10 to 300 kDa as recited in claim 1. Claimed ranges that overlap teachings of the prior art are prima facie obvious according to MPEP 2144.05(i).
Jones’ teaching for DIPEA in an amount of 0.5 – 6 x W, where W is the amount of free primary amino groups (paragraphs 0018, 0024, 0031), which is 50% to 600% of W, overlaps on the claimed range of 5 to 55% DIPEA as recited in claim 1. Claimed ranges that overlap teachings of the prior art are prima facie obvious according to MPEP 2144.05(i).
The combination of Fernandes’ teachings for chitosan as a non-viral drug delivery vector (paragraphs 0005 – 0007) with Jones’ teachings for reacting the primary amino groups of a polymer backbone with DIPEA (paragraphs 0018, 0031) reads on instant claim 2’s recitation for a chitosan-comprising a backbone with DIPEA covalently linked to the 6-hydroxyl group of to the amino group on C2.
Fernandes’s teaching that chitosan should have a molecular weight between 5 to 600 kDa and a degree of deacetylation from 70 to 95% (paragraph 0025) overlaps on the claimed ranges of 10 to 300 kDa and 70 to 99% deacetylation as recited in claim 3. Claimed ranges that overlap teachings of the prior art are prima facie obvious according to MPEP 2144.05(i).
Jones’ teaching for DIPEA in an amount of 0.5 – 6 x W, where W is the amount of free primary amino groups (paragraphs 0018, 0024, 0031), which is 50% to 600% of W, overlaps on the claimed range of 5 to 55% DIPEA as recited in claim 4. Claimed ranges that overlap teachings of the prior art are prima facie obvious according to MPEP 2144.05(i).
Jones’ teaching for PEG as a protective side chain that confers hydrophilicity and water-solubility to the polymer backbone (paragraph 0105) reads on instant claim 5.
Jones’ teaching that PEG has a size range between 2 to 20 kDa (paragraph 0105) overlaps on the instantly claimed range of 2 to 10 kDa as recited in claim 6. Claimed ranges that overlap teachings of the prior art are prima facie obvious according to MPEP 2144.05(i).
Jones does not teach the PEG substitution in an amount of 2 to 5%, however, 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 according to MPEP 2144.05(ii)(a). PEG is well-known in the art for conferring hydrophilicity, increasing water solubility, and being biocompatible . A person of ordinary skill in the art seeking to increase water solubility of a compound would be motivated to conjugate an appropriate amount of PEG, recognizing that the amount of PEG confers as certain amount of water solubility, thus the amount of PEG is a result-effective variable. As such, the presence of this result-effective variable would be motivation for a person of ordinary skill in the art to optimize the amount of PEG to obtain the desired result, which is prima facie obvious according to MPEP 2144.05(ii)(b). Thus claim 7 is prima facie obvious.
Fernandes’ teaching for a folic acid – chitosan conjugate (abstract, paragraphs 0017, 0025) reads on instant claims 8 and 9.
Fernandes’ teaching that nanoparticles comprising folic acid and chitosan contain or encapsulate DNA (paragraph 0018) reads on instant claims 10 and 11.
Conclusion
All claims are rejected. No claims are allowed.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Toriana N. Vigil whose telephone number is (571)270-7549. The examiner can normally be reached Monday - Friday 9:00 a.m. - 5:00 p.m. EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sahana Kaup can be reached at 571-272-6897. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TORIANA N. VIGIL/Examiner, Art Unit 1612
/SAHANA S KAUP/Supervisory Primary Examiner, Art Unit 1612
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