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 .
Claim Rejections - 35 USC § 103
Claim(s) 1 and 3-8 are rejected under 35 U.S.C. 103 as being unpatentable over Malette et al (4,394,373) in view of Singh et al (“Hemostatic Comparison of a Polysaccharide Powder and a Gelatin Powder”, Journal of Investigative Surgery, vol.32(5) (2019), pg.393-401), Hardy et al (US 2010/0092525 A1), Gittard et al (EP 2 968 651 B1) and Ngwabebhoh et al (“Adsorptive removal of multi-azo dye from aqueous phase using a semi-IPN superabsorbent chitosan-starch hydrogel”, Chemical Engineering Research and Design, vol.112 (2016), pg.274-288) (with Meena et al (“Study of locust bean gum reinforced cyst-chitosan and oxidized dextran based semi-IPN cryogel dressing for hemostatic application”, Bioactive Materials, vol.3 (2018), pg.370-384), which is being cited here merely to support the Examiner’s assertion that chitosan is a natural polymer that is biocompatible, mucoadhesive and degradable).
Malette teaches (abstract and col.2, lines 19-21, lines 34-36 and claims 1- 4) a method of achieving hemostasis in wounds by topically administering chitosan in a liquid or powder form (specifically, lyophilized powder form – see col.3, lines 39-46). Furthermore, Singh indicates (see pg.393, left-hand column, last two lines, right-hand column, first two lines) that among the various classes of hemostatic agents, powdered hemostats have been widely adopted for their ease-of-use. It would have been obvious to one skilled in the art to use chitosan in a powder form as Malette’s hemostatic agent for easier topical administration. Since chitosan is a natural polymer that is biocompatible, mucoadhesive and degradable (as evidenced by Meena (pg.370, left-hand column, 1st paragraph)), Malette’s chitosan is a bioadhesive polymer (BP).
Malette in view of Singh does not teach instant biodegradable superabsorbent polymer (Bio-SAP). Hardy teaches ([0063]-[0064]) superabsorbent materials that are also known to be hemostatic agents and teaches that these superabsorbent materials can be combined with other hemostatic agents. As an example for such superabsorbent materials, Hardy teaches chitosan superabsorbents (instant biodegradable superabsorbent polymer (Bio-SAP)). Because both Malette’s chitosan in a powder form and Hardy’s chitosan superabsorbents (i.e., chitosan based superabsorbent materials) are being individually taught to be useful for the same purpose (i.e., as hemostatic agents), it would have been obvious to one skilled in the art to combine Malette’s chitosan in a powder form with Hardy’s chitosan based superabsorbent material with a reasonable expectation of achieving enhanced hemostatic effects. MPEP 2144.06 states that “[i]t is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose . . . [T]he idea of combining them flows logically from their having been individually taught in the prior art.” In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980). Furthermore, as discussed above, since Singh teaches that powdered hemostats have been widely adopted for their ease-of-use, it would be obvious to make the whole composition containing Malette’s chitosan and Hardy’s chitosan based superabsorbent material in a powder form for easier topical administration.
With respect to the limitation “wherein the bioadhesive polymer (BP) comprises one or more selected from the group consisting of starch, chitosan chemically modified by thioglycolic acid (TGA), pullulan, . . . (GAGs), and derivatives thereof”, although Malette’s chitosan does not teach instant chitosan chemically modified by thioglycolic acid (TGA), Gittard teaches (claim 1) equivalency or interchangeability of chitosan and chitosan-thioglycolic acid, both as mucoadhesive agents in powder form used for protecting or treating (i.e., slowing or stopping bleeding at the site of the lesion – see [0017]) a lesion. Based on such teach of equivalency, it would have been obvious to one skilled in the art to use chitosan-thioglycolic acid (instant chitosan chemically modified by thioglycolic acid (TGA)) in a powder form in place of Malette’s chitosan in combination with Hardy’s chitosan superabsorbents with a reasonable expectation of success. Thus, Malette in view of Singh, Hardy and Gittard renders obvious instant topical hemostatic powder composition comprising instant Bio-SAP (chitosan superabsorbent as taught by Hardy) and instant BP (chitosan-thioglycolic acid as taught by Malette in view of Gittard), wherein the BP comprises chitosan chemically modified by thioglycolic acid (TGA).
With respect to the newly added limitation “the biodegradable superabsorbent polymer (Bio-SAP) comprises an interpenetrating polymer network (IPN) or semi interpenetrating polymer network (SIPN) structure formed by a crosslinking agent”, Malette in view of Singh, Hardy and Gittard does not teach that Hardy’s chitosan based superabsorbent material (instant Bio-SAP) comprises IPN or SIPN structure formed by a crosslinking agent. Ngwabebhoh teaches (abstract, pg.275, right-hand column, 2nd paragraph) a semi-IPN superabsorbent chitosan-starch hydrogel that has improved swelling and sorption capacity in aqueous solution. Ngwabebhoh teaches that the chemically crosslinked chitosan hydrogel via formation of a semi-IPN with starch enhances the hydrogel stability and swelling capacity. In Fig.3 (see also pg.278, left-hand column, last paragraph), Ngwabebhoh shows that the swelling rate increases rapidly reaching 1200% in 480 minutes and states (pg.278, right-hand column, 1st paragraph) that because of the fast and large degree of swelling, the hydrogel may be suitable for water related applications. Since Malette in view of Singh, Hardy and Gittard teaches the use of Hardy’s chitosan based superabsorbent material as a hemostatic agent (together with chitosan-thioglycolic acid (as taught by Malette in view of Gittard)), it would be obvious to one skilled in the art to use Ngwabebhoh’s semi-IPN (instant SIPN) chitosan-starch hydrogel as Hardy’s chitosan based superabsorbent material with a reasonable expectation of achieving rapid and large degree of swelling (besides, Hardy teaches ([0063]) that starch-based hemostats are also known in the art). Although Ngwabebhoh’s semi-IPN chitosan-starch hydrogel is not in a powder form, Hardy teaches ([0006]) that while hemostatic agents in the form of solid sheet materials are easier to handle, they conform less well than flowable hemostatic agents in powdered or granular form to the irregular surfaces and crevices typical of wounds ([0005]). Besides, as already discussed above, Singh indicates that it is known in the art that among the various classes of hemostatic agents, powdered hemostats have been widely adopted for their ease-of-use. Thus, it would be obvious to one skilled in the art to convert Ngwabebhoh’s semi-IPN chitosan-starch hydrogel to powdered form with a reasonable expectation that the semi-IPN superabsorbent chitosan-starch powder would conform to the irregular surfaces and crevices typical of wounds. Thus, Malette in view of Singh, Hardy, Gittard, and Ngwabebhoh renders obvious instant claims 1, 3, 4, 7 and 8 (as to claim 7, determining the optimum ratio between Bio-SAP (Hardy’s chitosan based superabsorbent material) and BP (chitosan-thioglycolic acid as taught by Malette in view of Gittard), which gives the best hemostatic effect would be within the realm of one of ordinary skill in the art).
With respect to instant claim 6, Ngwabebhoh teaches (pg.276, left-hand column, 1st paragraph, under section 2.2.2.) that the crosslinking agent used (in forming the semi-IPN structure) is glutaraldehyde. Thus, Malette in view of Singh, Hardy, Gittard, and Ngwabebhoh renders obvious instant claim 6.
With respect to instant claim 5, Ngwabebhoh does not explicitly teach the amount for the crosslinking agent. However, determining the optimum amount for the crosslinking agent that achieves the SIPN structure would be within the realm of one of ordinary skill in the art, and such amount would teach or at least overlap with instant range of claim 5 since both applicant and Ngwabebhoh seek to form SIPN structure from chitosan and starch using glutaldehyde (see Table 1 of present application). Thus, Malette in view of Singh, Hardy, Gittard, and Ngwabebhoh renders obvious instant claim 5.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Malette et al (4,394,373) in view of Singh et al (“Hemostatic Comparison of a Polysaccharide Powder and a Gelatin Powder”, Journal of Investigative Surgery, vol.32(5) (2019), pg.393-401), Hardy et al (US 2010/0092525 A1), Gittard et al (EP 2 968 651 B1) and Ngwabebhoh et al (“Adsorptive removal of multi-azo dye from aqueous phase using a semi-IPN superabsorbent chitosan-starch hydrogel”, Chemical Engineering Research and Design, vol.112 (2016), pg.274-288) as applied to claim 8 above, and further in view of Gagnieu et al (US 2014/0023714 A1).
Malette in view of Singh, Hardy, Gittard and Ngwabebhoh does not teach instant range for the average diameter of the topical hemostatic powder. However, Gagnieu teaches ([0168] and [0171]) that hemostatic powders should have a particle size range of 10-500 mm. If the powder is too small, then it is too pulverulent to properly reach the target, if it is too big, then the powder cannot be sprayed on the target. Gagnieu’s range (10-500 mm) falls within instant range (1-500 mm) and thus teaches instant range. Thus, Malette in view of Singh, Hardy, Gittard, Ngwabebhoh, and further in view of Gagnieu renders obvious instant claim 9.
Response to Arguments
Applicant first argue that one skilled in the art would not have been motivated to use Ngwabebhoh’s chemically crosslinked chitosan hydrogel in powder form because such a modification would have rendered Ngwabebhoh’s composition unsuitable for its intended purpose. However, US 2011/0251118 A1 (Bedford et al), a reference which teaches improved adsorption agents for removing dyes from aqueous solutions (see abstract), shows that hydrogels that have been dried and micronized can still be effective in removing dyes from aqueous solutions (see [0075], Examples 4 and 5, [0018]). Thus, the Examiner does not agree with applicant’s argument that one skilled in the art would not have been motivated to use Ngwabebhoh’s chemically crosslinked chitosan hydrogel in powder form because such modification would have rendered Ngwabebhoh’s composition unsuitable for its intended purpose. Applicant also argue that since Ngwabebhoh’s chemically crosslinked chitosan hydrogel is intended for adsorptive removal of multi-azo dye from aqueous base, one skilled in the art would not have been motivated to combine the teachings of Malette, Hardy and Ngwabebhoh since Malette and Hardy relate to hemostatic agents. However, as already discussed above, Ngwabebhoh teaches a semi-IPN superabsorbent chitosan-starch hydrogel that has improved swelling and sorption capacity in aqueous solution. Ngwabebhoh teaches that the chemically crosslinked chitosan hydrogel via formation of a semi-IPN with starch enhances the hydrogel stability and swelling capacity and thus may be suitable for water related applications. Since Malette in view of Singh, Hardy and Gittard teaches the use of Hardy’s chitosan based superabsorbent material as a hemostatic agent, it would be obvious to one skilled in the art to use Ngwabebhoh’s semi-IPN (instant SIPN) chitosan-starch hydrogel as Hardy’s chitosan based superabsorbent material with a reasonable expectation of achieving rapid and large degree of swelling. Besides, Hardy teaches ([0063]) that starch-based hemostats are also known in the art. Since both chitosan and starch are known to be used as hemostatic agents, it would be obvious to one skilled in the art to use Ngwabebhoh’s semi-IPN chitosan-starch hydrogel (which gives rapid and large degree of swelling) as Hardy’s chitosan-based superabsorbent material with a reasonable expectation of success.
For the reasons stated above, instant 103 rejections over Malette in view of Singh, Hardy, Gittard, and Ngwabebhoh still stand.
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/SIN J LEE/
Primary Examiner, Art Unit 1613
February 21, 2026