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 .
Detailed Action
This action is in response to the papers filed September 29, 2025.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 09/29/2025 has been entered.
Claim Amendments
Applicant’s amendments to the claims filed 09/29/2025 are acknowledged.
Claims 11-40 are pending.
Claim 21 is withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention.
Claims 11-20, 22-40 are under examination.
Election/Restrictions
The following is a summary of the restriction/election requirements in the application. See the Requirement for Restriction/Election mailed on 03/10/2025.
Applicant elected with traverse the invention of Group 1, drawn to a method for obtaining endometrial mesenchymal stem cells from human menstrual blood, in the reply filed 04/08/2025.
Claim 21 is withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 04/08/2025.
Priority
The instant application 17/907,318 was filed on 09/26/2022. This application is a national stage of international application PCT/CN2021/085202 filed 04/02/2021, claiming priority based on Chinese application CN202010259045.6 filed 04/03/2020.
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. While a certified copy of the foreign patent application is provided with the instant application, a certified English translation of said foreign patent application has not been provided.
Withdrawal of Prior Rejections/Objections
Rejections and/or objections not reiterated from the previous Office action mailed 08/12/2025 are hereby withdrawn. The following rejections and/or objections are either newly applied or are reiterated and are the only rejections and/or objections presently applied to the instant application.
Regarding the amendments to claim 11 and the written description requirement, applicant’s arguments filed 09/29/2025 are found persuasive.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 23-28 are rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
This rejection is newly applied.
Claim 13 recites the filter-through cell strainer has a mesh number of less than 30 mesh.
However, claims 23-28, each of which is dependent upon claim 13, recites the filter-through cell strainer has a mesh number of less than 35 mesh (claim 23), or less than 40 mesh (claim 24), or ranging from 18-60 mesh (claim 25), or ranging from 36-60 mesh (claim 26), or ranging from 36-50 mesh (claim 27), or ranging from 36-40 mesh (claim 28).
Accordingly, dependent claims 23-28 recite ranges of mesh numbers for the filter-through cell strainer that fall outside the scope of the range “less than 30 mesh,” as claimed in claim 13. Therefore, dependent claims 23-28 are improper dependent for broadening the scope of claim 13, or otherwise failing to include all the limitations thereof.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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.
Claims 11-14, 19-20, 22-30 and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Masuda et al. (2016) “An improved method for isolation of epithelial and stromal cells from the human endometrium” Journal of Reproduction and Development, 62(2), 213-218; in view of Ulrich et al. (2013) “Toward the use of endometrial and menstrual blood mesenchymal stem cells for cell-based therapies” Expert opinion on biological therapy, 13(10), 1387-1400.
This rejection is newly applied.
Masuda discloses a process of isolating epithelial and stromal cells (ECs and SCs) from isolated human endometrium (EM), comprising serial filtration of isolated EM fragments. Human endometrial tissue was collected in surgery and minced into pieces (tissue fragments). The tissue fragments were then separated into two fractions by filtration using a nylon mesh (440-μm diameter pores): the residual tissue fragments and the filtrate. This first filtrate was further separated into two fractions by filtration using a nylon mesh (40-μm diameter pores): the residual cell clumps and the second filtrate. The retentate containing residual cell clumps was seeded into a collagen-coated tissue culture dish and cultured as the endometrial epithelial cell (EMEC) fraction, and the dispersed cells in the second filtrate were seeded onto another collagen-coated tissue culture dish and cultured as the endometrial stromal cell (EMSC) fraction. See Abstract, pg. 213 and 217, and Figure 1A:
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The retentate (EMEC fraction) was found to contain both epithelial cells and stromal cells. See pg. 215, and Figure 1C. Stromal cells in the filtrate and retentate are found to read on “mesenchymal stem cells” and “adherent cells,” as claimed; the nylon meshes are found to read on “cell strainers,” as claimed; and the tissue fragments and cell clumps in the retentate are found to read on the “tissue debris.” Further, the cell culture medium used to culture the retentate is found to read on “a mesenchymal stem cells medium,” as claimed, because the media composition is suitable for mesenchymal stem cell culture. Therefore, Masuda is found to teach or fairly suggest a process for obtaining endometrial mesenchymal stem cells (stromal cells) from human endometrium, comprising:
subjecting a sample of endometrium to cascade filtration through graded cell strainers (nylon meshes) of increasing mesh numbers (increasing pore size) to separate tissue debris (tissue fragments and cell clumps), wherein said cell strainers include one or more filter-through cell strainers (first filtration) and one or more retention cell strainers (second filtration) for collecting retentate, wherein the mesh number of the one or more retention cell strainers (40-μm diameter pores) is larger than that of the one or more filter-through strainers (440-μm diameter pores);
collecting the retentate on the one or more retention cell strainers as the tissue debris (EMEC fraction);
culturing the tissue debris (EMEC fraction) in a mesenchymal stem cells medium; and
collecting adherent cells (EMEC and EMSC fraction) as the endometrial mesenchymal stem cells (stromal cells).
Accordingly, the difference between the instantly claimed process of claim 11 and that of Masuda is found to be a difference of input material into the process. Masuda collected the endometrial tissue during surgery of human subjects (biopsy); whereas, claim 11 recites the input material is menstrual blood (which contains endometrial tissue/cells).
Prior to the effective filing date of the instantly claimed invention, Ulrich teaches there are two methods for isolating endometrial stem/progenitor cells from the endometrium: (1) an endometrial biopsy from the uterine cavity or (2) collection of menstrual blood . See, e.g., Abstract; Article highlights on pg. 1388; Section 4 on pg. 1391; Conclusion on pg. 1396; and Figure 1:
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Therefore, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Masuda, which uses endometrial biopsy as the input material source of endometrial cells, by instead using human menstrual blood as the input material and source of endometrial cells, as taught by Ulrich, with a reasonable expectation of success because endometrial stem/progenitor cells may be isolated either from endometrial biopsy or menstrual blood, and menstrual blood is readily available source of endometrial stem/progenitor cells which may be collected non-invasively.
For these reasons, the process of claim 11 would have been prima facie obvious over the prior art.
Regarding dependent claims 12-13, 22-28, the claims recite that the one or more retention cell strainers has a mesh number ranging from 70-160 mesh (claim 12), or 80-160 mesh (claim 22); and the filter-through cell strainer has a mesh number of less than 30 mesh (claim 13), or less than 35 mesh (claim 23), or less than 40 mesh (claim 24), or ranging from 18-60 mesh (claim 25), or ranging from 36-60 mesh (claim 26), or ranging from 36-50 mesh (claim 27), or ranging from 36-40 mesh (claim 28).
As indicated above, Masuda discloses nylon meshes having 40-μm and 440-μm diameter pores. Masuda does not expressly disclose the mesh numbers recited by claims 12-13, 22-28.
[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
In this case, mesh number refers to the number of openings (pores) in one linear inch of a screen. Mesh number is not an exact measurement of pore size because the meshes may be made with various materials having different thickness of strands or wire. However, one of ordinary skill in the art would have recognized that increasing mesh number, as claimed, necessarily entails decreasing pore size. As discussed above, serial filtration through meshes of decreasing pore size, which necessarily entails increasing mesh number, is generally taught by Masuda. The first filtration using a nylon mesh having 440-μm diameter pores was used to retain the larger “tissue fragments,” and the second filtration using a nylon mesh having 40-μm diameter pores was used to retain the smaller “cell clumps,” whereby the dispersed cells (single/blood cells) were able to pass through in the filtrate. Accordingly, one of ordinary skill in the art would have recognized that mesh pore size, and consequently mesh number, is a result-effective variable influencing the quality of filtration, e.g., by controlling the size of the material retained in the filters rather than passing through into the filtrate. Therefore, one of ordinary skill in the art would have been led to optimize the mesh number of each filter through routine optimization. For these reasons, absent a secondary consideration, the claimed ranges of mesh numbers, as recited by claims 12-13, 22-28, would have been prima facie obvious over the prior art. See MPEP 2144.05.
Regarding dependent claims 14, 29-30, the claims recite the cascade filtration includes at least three grades of cell strainers (claim 14); at least four grades of cell strainers (claim 29); and two or more grades of filter-though and/or retention cell strainers (claim 30).
As indicated above, Masuda discloses cascade filtration including two grades of cell strainers (i.e., two meshes having 40-μm and 440-μm diameter pores). Masuda does not disclose more than two cell strainers in the process (Figure 1A).
[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
In a case where a person ordinarily skilled in the art can achieve an ordinary creativity of a person ordinarily skilled in the art, and where a sample containing a target cell contains a coarse tissue or a similar substance. It should be said that it was obvious to a person skllled in the art at the time of the priority date of the present application that a large quantity of samples can be rapidly separated while preventing clogging by passing strainers of larger pore size before strainers that retain target cells, and the recovery rate of target cells can be improved.
In this case, serial filtration through meshes of decreasing pore size, or increasing mesh number, is generally taught by Masuda. The first filtration using a nylon mesh having 440-μm diameter pores was used to retain the larger “tissue fragments,” and the second filtration using a nylon mesh having 40-μm diameter pores was used to retain the smaller “cell clumps,” whereby the dispersed cells (single/blood cells) were able to pass through in the filtrate. Accordingly, one of ordinary skill in the art would have recognized that the number of strainers (meshes) in serial filtration is a result-effective variable influencing the quality of filtration, e.g., by enabling larger quantities of samples to be separated while preventing clogging of the strainers, and improving recovery of target cells in the retentate and/or filtrate. Therefore, one of ordinary skill in the art would have been led to optimize the number of cell strainers (meshes) through routine optimization. For these reasons, absent a secondary consideration, the claimed number of cell strainers, as recited by claims 14, 29-30, would have been prima facie obvious over the prior art. See MPEP 2144.05.
Regarding dependent claim 19, the cell culture medium used to culture the retentate in Masuda is found to read on “amniocyte culture medium” as claimed, because the media composition is suitable for amniocyte cell culture.
Regarding dependent claims 20 and 40, the claims recite the tissue debris is cultured for 4-6 days (claim 20) or 5 days (claim 40). Masuda teaches the EMEC fraction was cultured for 5 days (pg. 217: “The EMEC outgrowths were trypsinized, collected, and counted for their cell numbers at 5 days after seeding.”)
Claims 15-18, 31-39 are rejected under 35 U.S.C. 103 as being unpatentable over Masuda et al. (2016) “An improved method for isolation of epithelial and stromal cells from the human endometrium” Journal of Reproduction and Development, 62(2), 213-218; and Ulrich et al. (2013) “Toward the use of endometrial and menstrual blood mesenchymal stem cells for cell-based therapies” Expert opinion on biological therapy, 13(10), 1387-1400, as applied to claims 11-14, 19-20, 22-30 and 40 above; in further view of Osteen et al. (1989) “Development of a method to isolate and culture highly purified populations of stromal and epithelial cells from human endometrial biopsy specimens” Fertility and sterility, 52(6), 965-972.
Regarding dependent claims 15-16, the claims recite the step of collecting the retentate includes releasing the tissue debris retained on the one or more retention cell strainers via back-flush with a washing fluid (claim 15) or washing the tissue debris with a washing fluid (claim 16).
Masuda does not expressly disclose a washing step to release the retentate from the cell strainers.
Prior to the effective filing date of the instantly claimed invention, Osteen discloses a process of isolating stromal and epithelial cells from a human endometrial biopsy sample by serial filtration. Endometrial tissue was dissected into small pieces, washed and enzymatically digested. The resulting cell suspension comprised stromal cells mostly as single cells and large clumps of epithelium. The cell suspension was then filtered sequentially though two mesh filters of 105 µm and 88 µm, respectively. Epithelial cell clumps, with some remaining stromal and endothelial components, were retained by the filters, which divided the tissue into "epithelial-enriched" and "stromal-enriched" fractions. The filtered stromal-enriched fraction was washed and separated further from epithelial cell clumps by differential sedimentation at unit gravity. The retained epithelial-enriched fraction was washed and enzymatically digested, thereby releasing the remaining stromal and endothelial cells from the cell clumps, and a purified epithelial preparation was finally achieved by unit gravity sedimentation followed by selective plating of any remaining stromal cells onto plastic substrate. See pg. 966-967, subsection titled: Tissue Dissociation and Cell Purification.
Osteen discloses that the retentate (epithelial-enriched fraction) was washed from the strainers using a phosphate buffer solution (HBSS). Pg. 967, left column.
Therefore, prior to the effective filing date of the instantly claimed invention, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Masuda to further include a step of releasing the retentate from the strainers by washing or back-flushing with a buffer solution, as taught by Osteen, with a reasonable expectation of success because the retentate contains target cells of the filtration process, and washing or back-flushing with a buffer solution is a suitable technique to release the target cells from the cell strainers.
Regarding dependent claims 17-18, Osteen discloses that the washing fluid is HBSS (pg. 967, left column), which is a phosphate buffer.
Regarding dependent claim 31, Masuda teaches that epithelial and stromal cells are retained in the nylon meshes (pg. 215; Figures 1A, C). Osteen pools the retentate from the mesh filters as the "epithelial-enriched" fraction (pg. 967, left column).
Regarding dependent claims 32-39, the claims recite the phosphate buffer (washing fluid) contains an antibiotic (claims 32 and 36); the antibiotic is gentamicin, penicillin, streptomycin, amphotericin B, or a combination thereof (claims 33 and 37); and the concentration of each antibiotic, if present, is 50-100 U/mL or 100 U/mL gentamicin, 180-200 U/mL or 200 U/mL penicillin, 0.15-0.2 mg/mL or 0.2 mg/mL streptomycin, or 4-5 µg/mL or 5 µg/mL amphotericin B (claims 34-35, 38-39).
Osteen does not expressly disclose use of an antibiotic in the washing fluid. Masuda used the antibiotic streptomycin prior to filtration (pg. 217, left column). Prior to the effective filing date of the instantly claimed invention, antibiotics, such as streptomycin, were used in cellular processes to eliminate and/or prevent bacterial contaminants (Official Notice taken, if necessary). Therefore, it would have been prima facie obvious to one of ordinary skill in the art to further include an antibiotic, such as streptomycin, in the phosphate buffer or washing fluid with a reasonable expectation of success in order to eliminate and/or prevent bacterial contaminants. As shown by Masuda, streptomycin was a suitable antibiotic for use in processing endometrial cells, as claimed in claims 33 and 37. Further, with regards to claims 34-35, 38-39, as instructed by MPEP 2144.05, differences in concentration will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration is critical. Therefore, absent a secondary consideration, the concentrations of antibiotics recited by claims 34-35, 38-39 would have been prima facie obvious over the prior art.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Du et al. (2016) “Endometrial mesenchymal stem cells isolated from menstrual blood by adherence” Stem Cells International, Volume 2016, Article ID 3573846, 8 pages, discloses the isolation of endometrial mesenchymal stem cells from menstrual blood by adherence to a plastic or glass substrate. See, e.g., Abstract, and pg. 1-2.
US 2023/0295577 A1, of record, discloses the separation of endometrial mesenchymal stem cells from menstrual blood by sequentially filtering the menstrual blood through an 18-mesh stainless cell strainer, a 36-mesh stainless cell strainer, an 80-mesh stainless cell strainer and a 100 μm filter membrane. The filtrate was further processed and cultured to obtained the endometrial mesenchymal stem cells. See paragraphs 87-93. A partial human-assisted machine translation (pg. 10, ll. 24-31; pg. 11, ll. 1-15) of the Chinese-language priority document, CN202010691416.8, filed on July 17, 2020, has been provided.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAMES J GRABER whose telephone number is (571)270-3988. The examiner can normally be reached Monday-Thursday: 9:00 am - 4:00 pm.
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/JAMES JOSEPH GRABER/Examiner, Art Unit 1631