Prosecution Insights
Last updated: April 18, 2026
Application No. 18/717,299

Cellulose Porous Particles, and Microcarrier for Culture Use which Comprises Same

Non-Final OA §103
Filed
Jun 06, 2024
Examiner
LE, HOA T
Art Unit
1788
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Asahi Kasei Kabushiki Kaisha
OA Round
1 (Non-Final)
73%
Grant Probability
Favorable
1-2
OA Rounds
3y 0m
To Grant
86%
With Interview

Examiner Intelligence

Grants 73% — above average
73%
Career Allow Rate
785 granted / 1080 resolved
+7.7% vs TC avg
Moderate +13% lift
Without
With
+13.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
45 currently pending
Career history
1125
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
37.3%
-2.7% vs TC avg
§102
29.6%
-10.4% vs TC avg
§112
23.2%
-16.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1080 resolved cases

Office Action

§103
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 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. Claims 1-6, 11-13 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over MA et al. (CN-102732475 B) Claim 1: Ma teaches a substrate comprising cellulose among other polysaccharides (translation copy, page 3, 6th paragraph); the cellulose is modified with a cationic substituent (i.e. positive charge) and then bonded with a polypeptide (Ma, translation copy, page 3, last paragraph). Cellulose is inherently porous. The cellulose is in the form of particles because the particle size diameter is described in Ma (translation copy, page 3). Alternatively, Ma does not explicitly describe whether the cellulose is porous. In the same field of endeavor, namely polypeptide bonded-cellulose particles, JP’086 teaches cellulose porous particles composed of cellulose, wherein the cellulose composing the cellulose porous particles having a polypeptide bonded to the cellulose (translation copy, page 5, 3rd paragraph). The cellulose porous particles include a spacer which is a hydrophilic polymer having a cationic group (translation copy, paragraph bridging pages 6, 1st and 2nd paragraph) and thus the surface of the cellulose is deemed to be modified with a cationic substituent. Claim 2: Ma teaches the charge density of the micro-carrier being most preferably 0.5 to 5 mmol/g dry (translation copy, page 3, 6th paragraph) which is the same as the claimed range. Claims 3-4: The polypeptide is an adhesive peptide, i.e. gelatin (translation copy page 3, 2nd paragraph) including at least an Arg-Gly-Asp fragment (translation copy, page 3, 3rd paragraph). Claims 5-6: Ma teaches the loading amount (dosage) of the polypeptide per cellulose being 100 mmol to 50 mmol/g (translation copy, page 5, 2nd paragraph) which overlaps the broad range of 10 nmol/g to 1 mmol/g. Claim 7: Because a fragment of the polypeptide includes Arg-Gly-Asp (see claims 3-4) above, the number of amino acid residues in the polypeptide is within the claimed range of 5 to 30 residues. Claim 11: Ma teaches the particle size of the porous particles (i.e. micro-carrier) being 50-800 µm (translation copy, page 3, 8th paragraph) which substantially overlaps the claimed range of mean particle size being from 100 µm to 1000 µm. Claims 12-13: Ma teaches the cationic substituent comprising an amino group (amine or amine salt) with preference to a tertiary amino group (NH2R1, NHR1R2, NR1R2R3 and R4-CO-NH-R5) (translation copy, page 5, 3rd paragraph). Claim 15: Ma teaches the micro-carrier is micro-carrier for cell culture (claim 1; translation copy, page 7, 1st paragraph). 4. Claims 1-13 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over MA et al. (CN-102732475 B) in view of HARA et al. (JP-2022063983 A) Claim 1: Ma teaches a substrate comprising cellulose among other polysaccharides (translation copy, page 3, 6th paragraph); the cellulose is modified with a cationic substituent (i.e. positive charge) and then bonded with a polypeptide (Ma, translation copy, page 3, last paragraph). The cellulose is in the form of particles because the particle size diameter is described in Ma (translation copy, page 3). Ma does not explicitly describe whether the cellulose is porous. In the same field of endeavor, namely modified-cellulose particles as carrier for cell culturing, Hara teaches cellulose porous particles being modified with a cationic substituents. The cellulose particles are porous (Hara, abstract). Hara states that porous microcarriers, the cells can be efficiently cultured and grown (translation copy, page 3, first paragraph). In light of Hara’s teaching regarding the advantages of porous cellulose, the POSITA would be motivated to utilize porous cellulose particles in the cellulose substrate of Ma. Claim 2: Ma teaches the charge density of the micro-carrier being most preferably 0.5 to 5 mmol/g dry (translation copy, page 3, 6th paragraph) which is the same as the claimed range. Claims 3-4: The polypeptide is an adhesive peptide, i.e. gelatin (translation copy page 3, 2nd paragraph) including at least an Arg-Gly-Asp fragment (translation copy, page 3, 3rd paragraph). Claims 5-6: Ma teaches the loading amount (dosage) of the polypeptide per cellulose being 100 mmol to 50 mmol/g (translation copy, page 5, 2nd paragraph) which overlaps the broad range of 10 nmol/g to 1 mmol/g. Claim 7: Because a fragment of the polypeptide includes Arg-Gly-Asp (see claims 3-4) above, the number of amino acid residues in the polypeptide is within the claimed range of 5 to 30 residues. Claim 8: Hara teaches the specific surface area of the dry cellulose porous particles is 0.3 m²/g to 4.4 m²/g (Hara, translation copy, page 3, 2nd paragraph). Claims 9-10: Hara teaches the cellulose having multiple pores, with a mean pore size of 5 µm to 100 µm, wherein the pores form a continuous pore structure with adjacent pores mutually communicating by openings in the membranes dividing them. (Hara, translation copy, page 2, 6th paragraph). Claim 11: Ma teaches the particle size of the porous particles (i.e. micro-carrier) being 50-800 µm (translation copy, page 3, 8th paragraph) which substantially overlaps the claimed range of 100 µm to 1000 µm. Additionally, Hara teaches porous cellulose having average particle size of 100 to 1000 mm (Hara, page 2, 6th paragraph), which is the same as the claimed range. Claims 12-13: Ma teaches the cationic substituent comprising an amino group (amine or amine salt) with a preference to a tertiary amino group (NH2R1, NHR1R2, NR1R2R3 and R4-CO-NH-R5) (translation copy, page 5, 3rd paragraph). Claim 15: Ma teaches the micro-carrier is micro-carrier for cell culture (claim 1; translation copy, page 7, 1st paragraph). Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Ma and Hara as applied to claims 1-13 and 15 above, and further in view of JP-04-173086 (“JP’086”)1 Ma and Hara teach the claimed cellulose porous particles as discussed above. Neither teaches the use of a spacer. In the same field of endeavor, namely cellulose particles bonded with a polypeptide to be used as carriers for cell culturing, JP’086 teaches cellulose porous particles composed of cellulose, wherein the cellulose composing the cellulose porous particles having a polypeptide bonded to the cellulose (translation copy, page 5, 3rd paragraph). JP’086 suggests the use of spacer in order to enhance the adhesion and spreading function of cells (JP’086, translation copy, page 6, first paragraph). Therefore, the POSITA would be motivated to interpose a spacer between the peptide and the cellulose particles of Ma as taught by JP’086. JP’086 teaches the spacer being polyethyleneimine (“PEI”) having a molecular weight of at least 3000 (translation copy, page 6); PEI has a base structure (CH2CH2NH)n which corresponds to a chain length of 8 atoms and thus falls within the claimed chain length range of 5 to 20 atoms. Any inquiry concerning this communication or earlier communications from the examiner should be directed to HOA (Holly) LE whose telephone number is (571)272-1511. The examiner can normally be reached Monday to Friday, 10:00 am to 7:00 pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Alicia Chevalier can be reached at 571-272-1490. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /HOA (Holly) LE/Primary Examiner, Art Unit 1788 1 Translation Copy provided by Applicant.
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Prosecution Timeline

Jun 06, 2024
Application Filed
Apr 01, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
73%
Grant Probability
86%
With Interview (+13.0%)
3y 0m
Median Time to Grant
Low
PTA Risk
Based on 1080 resolved cases by this examiner. Grant probability derived from career allow rate.

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