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 Status
Claims 1-9 are rejected.
Claims 10-18 are withdrawn.
No claims are allowed.
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application No. TW113114115, filed on 13-Sep-2024.
Information Disclosure Statement
The information disclosure statement(s) (IDS) submitted on 09-Sep-2024 and 22-Apr-2025 has been considered by the examiner.
Election/Restrictions
Applicant’s election without traverse of Group 1, Claims 1-9 in the reply filed on 24-Jun-2026 is acknowledged.
Accordingly, claims 10-18 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.
Claim Objections
Claim 4 objected to because of the following informalities:
Claim 4 recites the limitation "after the decellularizing the visceral tissues". This should be “after decellularizing the visceral tissue” for clarity.
Appropriate correction is required.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under pre-AIA 35 U.S.C. 103(a) 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 under pre-AIA 35 U.S.C. 103(a), the examiner presumes that the subject matter of the various claims was commonly owned at the time any inventions covered therein were made absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and invention dates of each claim that was not commonly owned at the time a later invention was made in order for the examiner to consider the applicability of pre-AIA 35 U.S.C. 103(c) and potential pre-AIA 35 U.S.C. 102(e), (f) or (g) prior art under pre-AIA 35 U.S.C. 103(a).
1. Claim(s) 1-2 and 7-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wolf et al. (A Hydrogel Derived From Decellularized Dermal Extracellular Matrix, Published: 01-Oct-2012) (hereinafter Wolf) in view of Hussey et al. (Ultrasonic cavitation to prepare ECM hydrogels, Published 05-Apr-2020) (hereinafter Hussey) and Kim et al. (US20210108180A1, Published: 15-Apr-2021, Filed: 30-Sep-2020) (hereinafter Kim).
Wolf teaches ECM hydrogels prepared from decellularized porcine urinary bladder (page 2, 2.1 Overview). Porcine urinary bladders from market weight pigs were harvested, and the urothelial, serosal, and muscular layers were removed by mechanical delamination (i.e., meeting providing visceral tissues of a pig). The remaining tissue consisted of intact basement membrane and tunica propria, which was rinsed with deionized water and then treated with 0.1% peracetic acid/4% ethanol on an orbital shaker at 300 RPM for 2 hours (i.e., meeting decellularizing the visceral tissues). The UBM (urinary bladder matrix) was then rinsed twice with PBS for 15 minutes each followed by two 15-minute rinses in deionized water. The UBM were frozen and lyophilized for use in hydrogel preparation. In brief, lyophilized ECM scaffolds were powdered using a Wiley Mill and filtered through a 40-mesh screen (i.e., meeting lyophilizing the extracellular matrix and grinding the extracellular matrix lyophilized into powder). The comminuted ECM was then enzymatically digested in a solution of 1 mg/ml porcine pepsin in 0.01 N HCl under a constant stir rate for 72 hours at room temperature (i.e., meeting performing a digestion process through an acidic solution). ECM pepsin digest stock solutions of 10 mg ECM/ml were frozen until use in subsequent experiments. Gelation was induced by neutralizing the pH and salt concentration of the pepsin digest at 4°C followed by warming to 37°C. Neutralization was accomplished by the addition of one-tenth the digest volume of 0.1 N NaOH, one-ninth the digest volume of 10X PBS, and then diluting to the desired final ECM concentration with 1X PBS while on ice (i.e., meeting performing a neutralization process through an alkaline solution). The neutralized digest (pre-gel) was then placed in a non-humidified incubator heated to 37°C for one hour, after which, a hydrogel had formed (i.e., meeting culturing the extracellular matrix hydrogel to gelatinize the extracellular matrix hydrogel). Thus, Wolf teaches culturing the extracellular matrix hydrogel under conditions sufficient to gelatinize the extracellular matrix hydrogel. ECM concentrations of 2, 4, 6, and 8 mg/ml were prepared (pages 2-3, 2.2. Preparation of D-ECM and UBM hydrogels). Further, Wolf teaches in figure 2B the storage modulus of the extracellular matrix hydrogel for concentrations of 4 mg/mL, 6 mg/mL, and 8 mg/mL (Page 17):
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Wolf differs from the instant claims insofar as not teaching homogenizing the visceral tissues prior to decellularization as distinct from the post decellularization lyophilization and grinding of the resultant product into powder, and not teaching sonication of the extracellular matrix hydrogel into a plurality of extracellular matrix nanoparticles with an ultrasonic homogenizer.
However, Hussey teaches a preparation of UBM wherein the matrix is sonicated with a Model 120 Sonic Dismembrator (Page 79). Hussey further teaches that ultrasonic cavitation can be used to solubilize ECM and prepare ECM hydrogels, and that ultrasonic processing provides an reduction in processing time compared to enzymatic digestion (Page 79, Introduction).
Kim teaches homogenizing via mincing whole visceral tissue prior to decellularization directed in the field of preparing decellularized extracellular matrix. Kim teaches “dECM (top) is produced by first isolating and mincing left ventricular myocardium from freshly harvested porcine hearts. Minced tissue is decellularized using a combination of detergents before being lyophilized” (Paragraph 19). Regarding instant claim 1 reciting homogenizing the visceral tissues, as noted in paragraph [0025] of the instant specification, in step S103, the visceral tissues were homogenized. For example, the lyophilized bladder tissues and the lyophilized lung tissues were further ground into small pieces using a laboratory grinder, respectively.
It would have been obvious to a person having ordinary skill in the art to modify the Wolf/Hussey combination to include a step of mincing/homogenizing the harvested visceral tissue prior to the decellularization process as taught by Kim. Kim discloses that mincing and decellularization are linked functionally since Kim performs the mincing of the bulk visceral tissue as the immediate prior step to detergent based decellularization. Kim does not disclose any other intervening purposes for the mincing step, and because the next step in Kim’s process is submersion of the minced tissues into decellularization detergent, a person having ordinary skill in the art would have understood from Kim’s disclosure that the mincing procedure before decellularization serves the function of increasing the exposed surface area of the tissue and reducing tissue thickness, and thereby enabling the decellularization detergents to more thoroughly remove cellular material. This same technical problem is shown in Wolf’s own process, and Wolf demonstrates adequate detergent penetration for their UBM composition by mechanical delaminating before treating with decellularization solutions.
Accordingly, 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 modify Wolf’s process to include Kim’s tissue mincing step prior to decellularization, and represents the combining of prior art elements according to known methods to yield predictable results.
As such, since Wolf teaches lyophilizing bladder tissues and powdering the lyophilized bladder tissues, Wolf teaches homogenizing the visceral tissues.
Regarding instant claim 7 reciting that when a concentration of the ECM hydrogel is 4 mg/mL, a storage modulus of the ECM hydrogel is in a range from 25 Pa to 35 Pa, Figure 2B of Wolf shows wherein the storage modulus at 4 mg/ml eventually reaches about 40 Pa in 10 min. Therefore, it would have been obvious that the hydrogel at 4 mg/ml would have a storage modulus range within the claimed ranged prior to reaching about 40 Pa. The claim does not recite a specific time for when the storage modulus value is to be measured.
Regarding instant claim 8 reciting that when a concentration of the ECM hydrogel is in a range from 6 mg/mL to 8 mg/mL, a storage modulus of the ECM hydrogel is in a range from 110 Pa to 120 Pa, Figure 2B of Wolf shows wherein the storage modulus at 8 mg/ml eventually reaches about 140 Pa in 10 min. Therefore, it would have been obvious that the hydrogel at 8 mg/ml would have a storage modulus range within the claimed ranged prior to reaching about 140 Pa. The claim does not recite a specific time for when the storage modulus value is to be measured.
2. Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wolf et al. (A Hydrogel Derived From Decellularized Dermal Extracellular Matrix, Published: 01-Oct-2012) (hereinafter Wolf) in view of Hussey et al. (Ultrasonic cavitation to prepare ECM hydrogels, Published 05-Apr-2020) (hereinafter Hussey) and Kim et al. (US20210108180A1, Published: 15-Apr-2021, Filed: 30-Sep-2020) (hereinafter Kim), and further in view of Chandru et al. (Human Cadaveric Donor Cornea Derived Extra Cellular Matrix Microparticles for Minimally Invasive Healing/Regeneration of Corneal Wounds, Published 02-Apr-2021) (hereinafter Chandru).
The teachings of Wolf and Hussey are discussed above. Wolf and Hussey do not teach that the extracellular matrix nanoparticles is less than 5 micrometers. For this reason, Chandru is added.
However, Chandru teaches a decellularized ECM composition that after processing results in extracellular nanoparticles with a size of about 2 micrometer (Page 6, Figure 2B):
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Further, Chandru teaches “dECM microparticles averaged <10 µm in size” (Page 19, Conclusion), and “Hydrogels with dECM concentrations higher than 30 mg/mL were not considered as it was difficult to mix this dECM/thrombin mixture with highly viscous fibrinogen solution which severely affected the homogenous distribution of the microparticles in the fibrin glue” (Page 7, 2.4. Hydrogel Preparation).
Accordingly, 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 formulated the extracellular matrix particles to be < 10 µm in size since the prior arts do not disclose a particle size and this is a known and effective size for extracellular matrix particles as taught by Chandru.
3. Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wolf et al. (A Hydrogel Derived From Decellularized Dermal Extracellular Matrix, Published: 01-Oct-2012) (hereinafter Wolf) in view of Hussey et al. (Ultrasonic cavitation to prepare ECM hydrogels, Published 05-Apr-2020) (hereinafter Hussey) and Kim et al. (US20210108180A1, Published: 15-Apr-2021, Filed: 30-Sep-2020) (hereinafter Kim), and further in view of Kao et al. (Characterization of Porcine Urinary Bladder Matrix Hydrogels from Sodium Dodecyl Sulfate Decellularization Method, Published 16-Dec-2020) (hereinafter Kao).
The teachings of Wolf and Hussey are discussed above. Wolf and Hussey does not teach that more than 98% of dsDNA is removed from the visceral tissues. For this reason, Kao is added.
However, Kao discloses under decellularization efficiency that after being prepared by physical delamination, native UBM was then decellularized, using PAA or SDS. The results from Picogreen (Figure 1A) showed that the concentration of remnant dsDNA in the SDS-treated group (10.9 ±2.7 ng/mg) was significantly lower than those of native UBM and PAA groups, with more than 98% of dsDNA being eliminated from the scaffolds. There was no significant difference in the cellular contents between native and PAA-treated UBM, indicating the ineffective decellularization effect of PAA(Page 5, 3.1. Decellularization Efficiency).
Accordingly, 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 modified the decellularization process of Wolf and Hussey with the decellularization conditions of Kao to obtain at least 98% of dsDNA removal since removing more than 98% dsDNA is efficient decellularization as taught by Kao.
4. Claim(s) 5-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wolf et al. (A Hydrogel Derived From Decellularized Dermal Extracellular Matrix, Published: 01-Oct-2012) (hereinafter Wolf) in view of Hussey et al. (Ultrasonic cavitation to prepare ECM hydrogels, Published 05-Apr-2020) (hereinafter Hussey) and Kim et al. (US20210108180A1, Published: 15-Apr-2021, Filed: 30-Sep-2020) (hereinafter Kim), and further in view of Freytes et al. (Preparation and rheological characterization of a gel form of the porcine urinary bladder matrix (Published 16-Jan-2008) (hereinafter Freytes).
The teachings of Wolf and Hussey are discussed above. Wolf and Hussey does not teach that the pH value of the acidic solution is in a range from 3 to 4 or that after neutralization, the pH value of the extracellular matrix hydrogel is in a range of 7.0 to 7.4. For this reason, Freytes is added.
Freytes discloses wherein “Peracetic acid residue was then removed with two 15-min phosphate-buffered saline (pH ¼ 7.4) washes, followed by two washes with sterile water for 15 min each. The decellularized UBM sheets were then lyophilized using an FTS Systems Bulk Freeze Dryer Model 8-54 and comminuted to a particulate form using a Wiley Mini Mill (Fig. 1A)” (Page 1631, 2.1. ECM preparation) and “One gram of lyophilized UBM powder (Fig. 1A) and 100 mg of pepsin (Sigma, w2000e2300 U/mg) were mixed in 100 ml of 0.01 M HCl and kept at a constant stir for 48 h at room temperature (25C). The resultant viscous solution of digested UBM or pre-gel solution had a pH of approximately 3.0-4.0 (Fig. 1B). The activity of pepsin was irreversibly inactivated when the pH was raised to 7.4 (see Section 2.4)” (Page 1631, 2.2. ECM digestion and solubilization).
In regard to claims 5 and 6, the pH ranges for the UBM is 3.0-4.0, and later neutralized to pH 7.4, thus teaching the limitations of claims 5 and 6, respectively.
It would have been prima facie obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the method of Wolf and Hussey by incorporating the pH conditions taught be Freytes. Wolf, Hussey, and Freytes are directed to the same subject matter, and a person having ordinary skill in the art would have been motivated to use the expressly disclosed pH conditions of Freytes in the corresponding UBM hydrogel preparation of Wolf and Hussey to provide the acidic conditions used for UBM digestion and to inactivate the pepsin prior to hydrogel formation, with a reasonable expectation of success.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to WENHAN LI whose telephone number is (571)272-9143. The examiner can normally be reached Monday-Friday 7:30 am-5 pm EST.
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/W.L./Examiner, Art Unit 1614 /ALI SOROUSH/Supervisory Patent Examiner, Art Unit 1614
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