Prosecution Insights
Last updated: April 19, 2026
Application No. 18/311,459

SPATIALLY CONTROLLED FABRICATION OF MULTI-SPHEROID TISSUES USING MAGNETIC BIOPRINTING

Non-Final OA §102§DP
Filed
May 03, 2023
Examiner
KNIGHT, TERESA E
Art Unit
1634
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
The Board Of Trustees Of The Leland Stanford Junior University
OA Round
1 (Non-Final)
65%
Grant Probability
Moderate
1-2
OA Rounds
3y 8m
To Grant
99%
With Interview

Examiner Intelligence

Grants 65% of resolved cases
65%
Career Allow Rate
307 granted / 475 resolved
+4.6% vs TC avg
Strong +50% interview lift
Without
With
+50.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 8m
Avg Prosecution
23 currently pending
Career history
498
Total Applications
across all art units

Statute-Specific Performance

§101
7.6%
-32.4% vs TC avg
§103
40.8%
+0.8% vs TC avg
§102
17.3%
-22.7% vs TC avg
§112
22.0%
-18.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 475 resolved cases

Office Action

§102 §DP
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 . Election/Restrictions Applicant’s election without traverse of Group I (claims 1-20) in the reply filed on Jan. 7, 2026 is acknowledged. The examiner apologizes, there has been an oversight in the restriction requirement dated Nov. 5, 2025. Claims 27-30 should have been placed in groups of their own, as they recite a broader method (one which does not require the product of Group I) than those recited in claims 21-26. III. Claims 27-30, drawn to a process of making a multi-spheroid tissue, not requiring 3D printing. Inventions of group I and III are drawn to an unrelated product and process. The inventions are distinct, as the process of Group III does not require the product of group I. Inventions of group II and III are drawn to an unrelated processes. The inventions are distinct, as the process of Group II requires the product of group I and group III does not require the product of group I. A search burden is present for the reasons explained in the rejection dated Nov. 5, 2025. Claims 1-20 are allowable. The restriction requirement, as set forth in the Office action mailed on Nov. 5, 2025, has been reconsidered in view of the allowability of claims to the elected invention pursuant to MPEP § 821.04(a). The restriction requirement is hereby withdrawn as to any claim that requires all the limitations of an allowable claim. Specifically, the restriction requirement of Nov. 5, 2025 is partially withdrawn. Claims 21-26, directed to process of using the allowable product and the product so made are no longer withdrawn from consideration because the claim(s) requires all the limitations of an allowable claim. However, claims 27-30, directed to subject matter not being rejoined remain withdrawn from consideration because they do not require all the limitations of an allowable claim. In view of the above noted withdrawal of the restriction requirement, applicant is advised that if any claim presented in a divisional application is anticipated by, or includes all the limitations of, a claim that is allowable in the present application, such claim may be subject to provisional statutory and/or nonstatutory double patenting rejections over the claims of the instant application. Once a restriction requirement is withdrawn, the provisions of 35 U.S.C. 121 are no longer applicable. See In re Ziegler, 443 F.2d 1211, 1215, 170 USPQ 129, 131-32 (CCPA 1971). See also MPEP § 804.01. Priority The application claims priority to provisional applications 63/337,794, filed May 3, 2022; as such the earliest possible priority date is May 3, 2022. Information Disclosure Statement The information disclosure statement filed Aug. 11, 2023 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the IDS has been considered by the examiner. Claim Rejections - 35 USC § 102 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. (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 25 and 26 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Baillargeon et al. (SLAS Technol., 2019, cited in IDS filed on Aug. 11, 2023). Claims 25 and 26 are directed to a multi-spheroid tissue produced by the method of claim 21 (claim 25), and a method of screening a candidate agent using the multi-spheroid tissue of claim 25 (claim 26). Claim 24 is a product-by-process claim, that is it recites the process that is used to create the product. Claim 25 depends from claim 24. "[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (emphasis added). MPEP 2113. Baillargeon et al. teach a magnetic 3D spheroid tissue that is useful for high-throughput screening (“screening of a candidate agent”). (Abstract, pg. 6-7 “Screening Assay”). Although Baillargeon et al. does not teach their spheroids are formed using the process of claim 21, the product of claim 24 does not require this process, if the product produced is the same as that produced using an alternate method. As both the claimed spheroid and that taught by Baillargeon et al. are spheroids that are useful in high throughput screening, it is asserted that the product taught by Baillargeon et al. is the same as the product produced using the process described in claim 21. Allowable Subject Matter Claims 1-24 are allowed. The following is an examiner’s statement of reasons for allowance: no reference teaches or renders obvious the claimed bioprinter which includes: a plurality of microwells capable of generating and culturing a plurality of spheroids; a reservoir including a support scaffold; a dual printhead including a first nozzle having an extrusion channel connected to a container containing magnetic ink and a second nozzle coupled to an electromagnet which is connected to a rod that is magnetized when the electromagnet is on and demagnetized when the electromagnet is turned off; and a processor that is programmed to perform the steps of coating a spheroid in the microwell with magnetic ink, then lowing a magnetized rod over the ink covered spheroid to attach the spheroid and moving the rod with the attached spheroid out of the microwell and to a position in the reservoir, then demagnetizing the rod to position the spheroid on support scaffold. Although the processer programming is considered to only be intended use (e.g. the device must be capable of performing these steps), the device is novel and non-obvious as its components (a plurality of microwells, a reservoir with a support scaffold and a container with magnetic ink) confine it to the context of 3D bioprinting and the recitation of a dual printhead with a first nozzle having an extrusion channel connected to a container containing magnetic ink and a second nozzle coupled to an electromagnet which is connected to a rod that is magnetized when the electromagnet is on and demagnetized when the electromagnet is turned off distinguish it over the prior art. The incorporation of magnetic nanoparticles into spheroids to permit manipulation of the spheroids into desired shapes, patterns or constructs is generally known (see Mattix (Biomaterials, 2014); Bowser (Biofabrication, 2020); Zhuang et al. (Intern’l J Bioprint, 2021); Caleffi et al. (Life Sciences, 2021); Ino et al. (Biotech and Bioengineer, 2007); Adine et al. (Biomaterials, 2018); all cited in IDS filed on Aug. 11, 2023), the magnetic manipulation either occurs before bioprinting (magnetized cells for spheroids, which are then printed) or after bioprinting (printed cells or spheroids can be magnetically manipulated using dots or other magnetic controls that are present in the petri dish/wells that the cells have been printed into. No reference teaches using a bioprinter to coat spheroids (or cells) with magnetic ink (first nozzle), then using a magnetic rod to (second nozzle) attach and move the coated spheroid to a support scaffold. The closest prior art, Bowser et al. (Biofabrication, 2020), teaches bioprinting of spheroids into hydrogel constructs, using a custom designed tool to align a magnet below the porous membrane, then removing spheroids and inserting them into a void in hydrogel by using the magnetic tool underneath the porous membrane. (whole document, esp. pg. 4, 2.4. Constructing CNS microphysiological model). The following references are pertinent, but do not offer closer art than that cited by applicants. Abdel Fattah et al. (U.S Patent App. No. 2019/0127685 A1) teaches contactless, label-free, 3D printing of non-adherent and adherent cells, which involves using the cells’ inherent diamagnetic properties and placing them in a nontoxic paramagnetic medium to manipulate the cell and enable positioning. Notably, Abdel Fattah et al. teaches this method does not require the use of a nozzle, as they can contaminate the cell suspension or provide a surface for the cell to adhere to. Mishriki et al. (AAAS Research, 2019) teach a contactless label-free, 3D printing method using diamagnetophoretic ink with MCF-7 cells suspended in culture medium that includes a paramagnetic salt, enabling application of a magnetic field to position the cells on a ultralow attachment surface. Ajiteru et al. (Biofabrication, 2021) teaches a 3D printed magnetic bioreactor system; notably, the article focuses on systems which apply a magnetic field to cells that have been placed and can continue magnetic stimulation to induce proper cell growth and/or differentiation. Table 1 provides a summary of references that employ magneto-mechanical stimulation during placement and culturing of cells. Any inquiry concerning this communication or earlier communications from the examiner should be directed to TERESA E KNIGHT whose telephone number is (571)272-2840. The examiner can normally be reached Monday-Friday 9-4. 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, Maria Leavitt can be reached at 571-272-1085. 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. /TERESA E KNIGHT/ Primary Examiner, Art Unit 1634
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Prosecution Timeline

May 03, 2023
Application Filed
Feb 21, 2026
Non-Final Rejection — §102, §DP (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
65%
Grant Probability
99%
With Interview (+50.4%)
3y 8m
Median Time to Grant
Low
PTA Risk
Based on 475 resolved cases by this examiner. Grant probability derived from career allow rate.

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