DETAILED ACTION
Status of the Application
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 16-17, 19, 28-30, 32, 34, 38-39, 41-42, 45, 49, 51, and 60 are withdrawn.
Claims 1-2, 4, 13, and 15 are pending and represent all claims currently under consideration.
Response to Amendment
The amendment filed 11/24/2025 has been entered.
Claims 1-2, 13, and 15 were amended. No new material was added.
Applicant’s amendments have overcome the previous objections to the specification and claims; the rejection under 35 U.S.C. 112(b) of claim 13; and the rejection of claims 1 and 4 under 35 U.S.C. 102.
The rejection of claims 1-2, 4, 13, and 15 under 35 U.S.C. 103 has been modified to address the amendments and maintained.
Response to Arguments
Applicant’s arguments, see Remarks (pages 17-18), filed 11/24/2025, with respect to the rejection of claims 1 and 4 under 35 U.S.C. 102 have been fully considered and are persuasive due to the amendment of claim 1. The rejection of claims 1 and 4 has been withdrawn.
Applicant's arguments with respect to the rejection of claims 1-2, 4, 13, and 15 under 35 U.S.C. 103 have been fully considered but they are not persuasive.
Applicant argues that one skilled in the art would understand Delisle to teach an encapsulated therapeutic agent can be a silk fibroin particle or a therapeutic agent can be encapsulated together with a silk fibroin particle, and not encapsulation of a therapeutic aid by silk fibroin. Applicant further states Delisle fails to teach or suggest a silk fibroin particle microsphere and nanosphere that encapsulates any therapeutic acid or an oxygen carrier (Remarks, page 18, paragraphs 3-5). This argument is not persuasive, because as stated previously, Delisle teaches encapsulation of a therapeutic agent or cargo with another substance such as silk-based product formulations (Delisle, page 44, paragraph 0115), and teaches silk-based product formulations include silk fibroin particles (Delisle, page 151, paragraph 0348). To further support that the encapsulation of the therapeutic agent with a silk-based product formulation reads on the encapsulation of a therapeutic aid by a silk-based product, rather than together with a silk-based product, as suggested in the Remarks, Delisle also states SBPs may be used to encapsulate therapeutic agents (Delisle, page 182, paragraph 0429), which supports the Examiner’s interpretation.
Applicant argues that Delisle fails to teach or suggest formation of a silk particle that encapsulates an oxygen carrier formed by a lipid micelle encapsulation method or a phase separation (Remarks, page 19, paragraph 1). As stated previously, Delisle teaches the product as claimed, and the patentability of a product does not depend on its method of production, and the determination of patentability is based on the product itself. See MPEP § 2113(I). However, it is noted that Delisle further teaches dispersing the processed silk in a solution with a lipid (Delisle, page 79, paragraph 0215), resulting in the silk fibroin particles encapsulated within the lipid vesicle (i.e., a lipid micelle encapsulation method; Delisle, page 113, paragraph 0235).
Applicant argues that Delisle teaches a perfluorocarbon as a detectable label, which is structurally different from perfluorocarbons suitable for use as an oxygen carrier (Remarks, page 19, paragraph 2). This argument is not persuasive, because as stated in the instant specification, perfluorooctyl bromide is an example of a suitable perfluorocarbon oxygen carrier (specification, page 3, paragraph 12). As evidenced by PubChem (PubChem, Perfluorooctyl bromide), perfluorooctyl bromide is known to be used as both an oxygen carrier and as a contrast agent for MRI (i.e., as a detectable label). Therefore, detectable perfluorocarbons are not known to be structurally different from oxygen carrying perfluorocarbons.
Applicant argues that Delisle does not teach or suggest a silk fibroin particle having a diameter less than 100 nM in diameter as in claim 1 or a silk fibroin particle about 200 to 500 nm in diameter as in claim 2, and further states that Delisle merely discloses an exceptionally broad range of 10 nm up to 100 mm, citing a smaller range as critical (Remarks, page 19, paragraph 3). This argument is not persuasive, because there is no evidence provided in the specification to suggest the smaller range is critical. The applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range. See MPEP 2144.05(III)(A). It is also noted that the currently amended claim 1 teaches a diameter of less than 1000 nm (i.e., 1 micrometer), not 100 nM as stated in the Remarks. As stated in the previous rejection, Delisle teaches silk fibroin particles can have a width of from about 0.05 micrometers (i.e., 50 nm) to about 10 micrometers (Delisle, page 152, paragraph 0348), which is also smaller than the range stated in the Remarks.
Applicant states that a combination of particle size and encapsulation of an oxygen carrier is only apparent from Delisle by using impermissible hindsight gained from Applicant’s disclosure (Remarks, page 19, paragraph 3). This argument is not persuasive, because Delisle teaches both the particle size and encapsulation of an oxygen carrier as discussed in the rejection below. It would have been prima facie obvious to one of ordinary skill in the art to use a particle size taught by Delisle when encapsulating a therapeutic material as taught by the same reference.
Modified/Maintained Claim Rejections - 35 USC § 103The 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.
Claims 1-2, 4, 13, and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Delisle (WO 2019236525 A1; IDS reference, 03/28/2024). The reference was previously cited by the Examiner.
Regarding claim 1, Delisle teaches silk-based product formulations (Delisle, abstract) including silk fibroin particles (Delisle, page 151, paragraph 0348), which encapsulate therapeutic agents (Delisle, page 44, paragraph 0115) such as perfluorocarbons (i.e., an oxygen carrier listed in claim 4; Delisle, page 174, paragraph 0405). Delisle teaches the formulation can be administered at a dose sufficient to yield a desired therapeutic agent concentration in the blood (i.e., a blood substitute; Delisle, page 252, paragraph 0512). Delisle teaches silk fibroin particles can have a width of from about 0.05 micrometers (i.e., 50 nm) to about 10 micrometers (Delisle, page 152, paragraph 0348), which overlaps the claimed range of less than 1000 nm, and which suggests the silk fibroin particles can be silk fibroin nanoparticles. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP §2144.05(I).
Delisle is considered to be analogous to the claimed invention, because both Delisle and the instant invention are in the same field of silk fibroin particles. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have arrived at the claimed invention based on the teachings of Delisle under the meaning of 35 U.S.C. 103.
Regarding claim 2, Delisle teaches all the elements of the current invention as applied to claim 1. Delisle teaches silk fibroin particles can have a width of from about 0.05 micrometers (i.e., 50 nm) to about 10 micrometers (Delisle, page 152, paragraph 0349), which encompasses the claimed range of about 200 to about 500 nm. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP §2144.05(I).
Regarding claim 4, Delisle teaches all the elements of the current invention as applied to claim 1. Delisle teaches therapeutic agents (Delisle, page 44, paragraph 0115) to include perfluorocarbons (Delisle, page 174, paragraph 0405).
Regarding claim 13, Delisle teaches all the elements of the current invention as applied to claim 1. As discussed above, Delisle teaches silk fibroin particles (Delisle, page 151, paragraph 0348), which encapsulate therapeutic agents (Delisle, page 44, paragraph 0115) such as perfluorocarbons (i.e., an oxygen carrier listed in claim 4; Delisle, page 174, paragraph 0405). This claim is considered to be a product-by-process type claim. The patentability of a product does not depend on its method of production, and the determination of patentability is based on the product itself. See MPEP § 2113(I). However, it is noted that Delisle further teaches raw silk is processed by degumming (Delisle, page 27, paragraph 0060) and teaches degumming for a time of 60 minutes (Delisle, claim 6), which lies within the claimed range of 15 minutes to 2 hours and matches the claimed time of 60 minutes.
Regarding claim 15, Delisle teaches all the elements of the current invention as applied to claim 13. As discussed above, Delisle teaches silk fibroin particles (Delisle, page 151, paragraph 0348), which encapsulate therapeutic agents (Delisle, page 44, paragraph 0115) such as perfluorocarbons (i.e., an oxygen carrier listed in claim 4; Delisle, page 174, paragraph 0405). This claim is considered to be a product-by-process type claim. The patentability of a product does not depend on its method of production, and the determination of patentability is based on the product itself. See MPEP § 2113(I). However, it is noted that Delisle further teaches dispersing the processed silk in a solution with a lipid (Delisle, page 79, paragraph 0215), resulting in the silk fibroin particles encapsulated within the lipid vesicle (i.e., a lipid micelle encapsulation method; Delisle, page 113, paragraph 0235).
Conclusion
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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/C.P.J./Examiner, Art Unit 1613
/JENNIFER A BERRIOS/ Primary Examiner, Art Unit 1613