Prosecution Insights
Last updated: April 19, 2026
Application No. 17/925,957

HYDROGEL PRODUCING DEVICE FOR SAMPLING OF THE INTESTINAL LUMEN

Final Rejection §103
Filed
Nov 17, 2022
Examiner
MITCHELL, EDWIN COLEMAN
Art Unit
1619
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Danmarks Tekniske Universitet
OA Round
2 (Final)
31%
Grant Probability
At Risk
3-4
OA Rounds
3y 10m
To Grant
94%
With Interview

Examiner Intelligence

Grants only 31% of cases
31%
Career Allow Rate
28 granted / 90 resolved
-28.9% vs TC avg
Strong +63% interview lift
Without
With
+62.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 10m
Avg Prosecution
67 currently pending
Career history
157
Total Applications
across all art units

Statute-Specific Performance

§101
2.0%
-38.0% vs TC avg
§103
46.1%
+6.1% vs TC avg
§102
7.0%
-33.0% vs TC avg
§112
28.3%
-11.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 90 resolved cases

Office Action

§103
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 Response to Amendment Status of the Claims Receipt of Applicant’s response, filed 17 Oct 2025 has been entered. Claims 1 and 47-65 remain pending in the application. Claims 48, 50, 51, 54, 55 and 63 are amended. Claim 2-46 are cancelled. Claims 64 and 65 are withdrawn from further consideration by the examiner, 37 CFR 1.142(b), as being drawn to a non-elected invention. Claims 1 and 47-63 are under consideration to the extent of the elected species, i.e., that the hydrogel prepolymer is PEGDA, the radial initiator is iron trichloride, the non-biodegradable, biocompatible polymer is SU-8, the contrast agent is barium based and the extraction component is a magnetic material. Objections Withdrawn Objections to the Specification The specification objections set forth in the Non-Final Office Action mailed 17 Jul 2025 are hereby withdrawn in light of applicant’s amendments of the specification. Objections to the Claims The claim objections set forth in the Non-Final Office Action mailed 17 Jul 2025 are hereby withdrawn in light of applicant’s amendments of the claims. Rejections Withdrawn Rejections Pursuant to 35 USC § 112 The rejections of claims 48, 50, and 51 pursuant to 35 U.S.C. 112(b) set forth in the Non-Final Office Action mailed 17 Jul 2025 are hereby withdrawn in light of applicant’s amendment of the claims. The rejection of claim 63 pursuant to 35 U.S.C. 112(d) set forth in the Non-Final Office Action mailed 17 Jul 2025 is hereby withdrawn in light of applicant’s amendment of the claims. Rejections Maintained 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. 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1 and 47-63 are rejected under 35 U.S.C. 103 as being unpatentable over Shalon (WO 2018/213729, published 22 Nov 2018) in view of Beckman et al. (US 2005/0234336, published 20 Oct 2005, listed on IDS filed 4 Feb 2023), Rescigno et al. (US 2018/0333428, published 22 Nov 2018, listed on IDS filed 4 Feb 2023), Sun et al. (J. Mater. Chem. B, 2013, 1,3932), Choi et al. (Adv Healthc Mater. 2019 September ; 8(17)) and Petersen ((2015) Fabrication and loading of microcontainers for oral drug delivery. DTU Nanotech) as evidenced by Capsule Fillers (Capsule Size Guide). Shalon teaches embodiments of devices and methods of collecting gastrointestinal samples using a capsule-shaped device that is swallowed (abstract). Shalon teaches the device comprises a capsule with a tube-shaped body comprising an open end and a closed end ([0006]) where the tube-shaped body is placed inside the capsule ([0017]). A body with a tube shape comprising an opening renders obvious an “open container” that is cylindrical as in claims 53-55. Shalon teaches that the tube shaped body comprises the degradation of a covering element ([0022]), rendering obvious a lid element and dissolution of a dissolvable block as in claims 56 and 58. Shalon additionally teaches that the body may comprise a sealing element movable from a first position where the opening is open to a second position where the opening is sealed by the sealing and an actuator configured to move the sealing element ([0026]). Shalon further teaches an embodiment where a latch mechanism activates and locks to prevent separation of a seal and exposure of collecting members to the outside environment ([0176]), rendering obvious a lid element opened and closed by a lid mechanism as in claims 56 and 57. Shalon teaches that inclusion of a hydrogel designed to expand as a function of various pH levels in order to optimize sampling at specific regions ([0112], [0113]). Shalon teaches dehydrated superabsorbent materials for the hydrogels ([0132]) and teaches coating the lumen of the tube-shaped body with a hydrogel, rendering obvious a dry composition and a hydrogel pre-polymer as in claim 1 and positioning the hydrogel inside the container as in claim 63. Shalon teaches that the hydrogel may be an actuator that expands when wet to create a plug blocking opening ([0132]). Shalon teaches that the tube-shaped body or an opening of the tube-shaped body may be covered with an enteric degradable material ([0018]), rendering obvious an enteric coating as in claim 1 and covering the open container with the enteric coating as in claim 63. Shalon teaches that the body must fit inside a capsule of size 000 or smaller ([0163]). As evidenced by Capsule Filler, a size 000 capsule has a length of 1.029 inches (26.1 mm) and a diameter of 9.91 mm (pages 1 and 2 of chart) and thus the size 000 or less taught by Shalon renders obvious the capsule dimensions of claim 59. Shalon teaches that the device may contain a radio-opaque marker to make the capsule visible in x-rays or fluoroscopy ([0285]). Shalon teaches that the inclusion of a magnetic or ferromagnetic attraction element which serves to aid recovery of the device in the toilet bowl ([0179]), rendering obvious the magnetic material extraction component of claims 1 and 62. Shalon teaches that the tube shaped body is non-dissolvable ([0250]), but does not teach the elected species of polymer SU-8. Shalon does not teach the inclusion of a radical initiator such as iron trichloride (the elected species) or that the polymer for the hydrogel is PEGDA (the elected species) or that the radio-opaque marker is barium based (the contrast agent of claims 60-61). These deficiencies are made up for in the teachings of Beckman, Rescigno, Sun, Choi and Petersen. Beckman teaches methods and materials for implantable devises and visualization of the devices (abstract). Beckman teaches the devices with the marker is visible under x-ray ([0017]) using radiopaque materials or elements such as barium containing compounds ([0033], [0068]). Beckman further teaches hydrogels from polymers with include substituents that are cross-linked by a radical reaction upon contact with a radical initiator ([0121], [0122]). Rescigno teaches administering a hydrogel to the gastrointestinal tract of a subject (abstract). Rescigno teaches that the hydrogels can be modulated by administering a xerogel formulation which sells only under specific environmental conditions such as pH ([0074]) and Rescigno teaches hydrogel swelling and shrinking as finely regulated by changes of external GI environment pH and ionic strength ([0075]). Rescigno teaches hydrogels formed from a crosslinked addition polymer such as a crosslinked polyacrylate or a crosslinked acrylate copolymer with a neutral monomer such acrylamide and crosslinked using methods known in the art, such as a hydrogel comprising polyethylene glycol diacrylate (PEGDA) with an average molecular weight ranging from 250-20,000 Da (i.e. g/mol), such as 575 Da ([0035]). Sun teaches the formation of a biocompatible hydrogels formed by Fenton reaction initiated polymerization (abstract). Sun teaches that redox systems generating free radicals, such as the redox pair of hydrogen peroxide and ferrous salt, initiate the crosslinking process (page 3932 right column). The Fenton system involves hydrogen peroxide and ferrous salts to generate highly reactive hydroxyl radicals and Fenton’s reagent has been used as a radical initiator in polymerization for many years (page 3932 right column, page 3935 right column). Sun teaches the use of Fenton’s reaction with ferrous chloride to form robust PEGDA hydrogels (page 3933 left column). Choi similarly teaches the use of the Fenton reaction for forming hydrogels (title) but uses Fe(III) ions instead of ferrous ions (abstract). Choi teaches that the Fenton reaction is extensively employed as a radical initiator (page 1 right column last paragraph) and that Fe(III) is a product of the Fe(II) oxidation in the Fenton reaction but that Fe(III) may be reduced to Fe(II) via ascorbic acid and may subsequently undergo the oxidation via the Fenton reaction (page 2 scheme 1). Choi teaches the use of FeCl3 for the source of iron(III) for the Fenton reaction (page 10 right column). Petersen teaches the fabrication of microcontainers for oral delivery (title) with controlled size of reservoirs that can be loaded with drug in a precise manner (page 3 section 1.2). Petersen teaches that the ideal device has drug release unidirectional, preferably controlled by a biodegradable or pH-sensitive membrane (page 3 section 1.2 point 5). Petersen teaches that reservoir devices have been produced with photoresists such as SU-8 (page 4 section 1.3.1). Petersen teaches that SU-8 is biocompatible and can be used with implantable devices and that SU-8 is not biodegradable (page 16 section 2.1.1). Therefore, 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 used SU-8 to form the tube shaped body of Shalon and to include FeCl3 and ascorbic acid as initiators for hydrogel formation with PEGDA (250-20,000 Da)and to include barium based radiopaque markers in the capsules. The inclusion of radio-opaque markers to make the capsules visible in x-rays is known from the teachings of Shalon and barium containing compounds are known radiopaque materials that may be used in implantable devices for visualization, as taught by Beckman. Thus, one would have a reasonable expectation of success in using barium containing compounds as they are known to be suitable in patients and are radiopaque and thus serve to aid in visualization via x-rays. The hydrogels of Shalon are designed to expand as a function of various pH levels to optimize sampling in specific regions and PEGDA is a hydrogel suitable for use in the gastrointestinal tract where the swelling and shrinking may be regulated by changes of external GI environmental pH, as taught by Rescigno, providing a reasonable expectation of success in using PEGDA as the hydrogel material in the capsules of Shalon. It is further known from Sun and Choi that the Fenton reaction is well known for establishing radicals and that may be used in initiating crosslinking processes used for hydrogel formation and Sun makes it clear that the Fenton reaction is useful in forming PEGDA hydrogels. It is further known from Choi that the Fenton reaction may be utilized by employing FeCl3 in combination with ascorbic acid as the ascorbic acid reduces the iron(III) to iron(II). Thus, it is obvious to use a Fenton type reaction with iron chloride in order to initiate PEGDA hydrogel formation and the combination of iron trichloride and ascorbic acid is another means of achieving this reaction, rendering their inclusion and mixture with PEGDA as obvious for their ability to aid in hydrogel formation. Regarding claim 51 and the encapsulation of the radical initiator, as described above, material such as the hydrogel is located inside the lumen of the tube-shaped body and may be used as a plug to block the opening, as taught by Shalon, thus rendering it obvious that the initiator would be fully encapsulated by the container and the pre-polymer. Additionally, the capsules of Shalon comprise tube shaped body inside the capsule that is a non-dissolvable and the hydrogel is in the lumen of the tube shaped body. The polymer SU-8 is known to be biocompatible and not biodegradable and is a photoresist material that may be formed into reservoir devices for loading drugs. Thus, it would be obvious to use SU-8 as the material for the tube shaped body taught by Shalon as it is non-biodegradable and thus won’t dissolve and it may be formed into reservoir shapes that can hold material, providing a reasonable expectation of success in SU-8 retaining the hydrogel material, as taught by Shalon. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, as evidenced by the references. Response to Arguments Applicant's arguments filed 17 Oct 2025 have been fully considered but they are not persuasive. Applicant argues that the art does not teach the use of a pre-polymer in place of a hydrogel in an oral delivery capsule (page 9 of remarks). The applicant argues that using a hydrogel pre-polymer has an advantage over a preformed hydrogel in that it is more effective in entrapping the gut microbiome (page 9 of remarks). The applicant points to example 7 of the instant specification for evidence of improved bacterial absorption when using a pre-polymer vs an already polymerized hydrogel (page 9 of remarks). The applicant argues that the art does not provide motivation to “entirely change the way the way that the Shalon system functions” (page 10 of remarks). The examiner is not persuaded by these arguments. The examiner does not agree that the incorporation of PEGDA pre-polymer and an initiator would entirely change the way the system of Shalon functions but instead sees this as an alternative hydrogel option fully compatible with the system of Shalon. Shalon teaches that the hydrogel material is dehydrated and is designed to expand as a function of various pH levels in order to optimize sampling at specific regions ([0112-0113], [0132]). Thus, it is obvious that the hydrogel is meant to perform collection at a specific desired region and is not meant to expand or collect or perform its function until at a specific location. In contrast to the applicant’s assertion that the use of a pre-polymer would change the way the system of Shalon functions, the examiner sees the use of a pre-polymer system with an initiator as compatible with Shalon as it is similar to having the hydrogel dehydrated and supports the goal of limiting sampling until at a specific desired location. Forming a hydrogel with radical initiators and where the hydrogel is formed in a body is a known means of hydrogel formation (e.g. see Beckman [0117], Sun page 3932 left column) and there is nothing to indicate that this would be against the invention of Shalon but rather, as noted above, it would be in line with and supportive of the desires of Shalon to have a hydrogel material dehydrated and responsive only at a specific location. The fact that Shalon does not teach the polymer/initiator combination in the device does not indicate that such a combination would be against the teachings of Shalon or that it would be non-obvious. The formation of a pH responsive PEGDA hydrogel is known in the art, as well as the incorporation of hydrogels formed by initiators into implantable devices, as described above, and one or ordinary skill would recognize the formation of a PEGDA hydrogel in the device of Shalon as compatible with the device and supportive of the intention of location specific collection. The applicant highlights data in Table 3 of the instant specification to indicate the difference between the instant invention and the hydrogel of Shalon, but the examiner does not find this data persuasive. The data does not accurately compare the hydrogel of Shalon with the instant invention. The examiner notes that the control formulation was prepared by pre-activating the hydrogel components with PBS and that the bacterial suspension was introduced after gel formation (page 29 lines 9-12). The examiner does not find it surprising that the hydrogel that formed with bacteria present contained more bacteria than the hydrogel already formed and in a gel state that was subsequently exposed to bacteria as the hydrogel was already filled with material. This is not a similar comparison to the teachings of Shalon where the hydrogel was in a dehydrated state. The examiner notes that if the applicant desires to show unexpected results that the data should be a comparison to the closest prior art and additionally that the data presented should be commensurate in scope with the claim limitations. Conclusion No claims are allowed. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 extension fee 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 date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to EDWIN C MITCHELL whose telephone number is (571)272-7007. The examiner can normally be reached Mon-Fri 8:00-5:00. 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, David Blanchard can be reached on (571)272-0827. 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. /E.C.M./Examiner, Art Unit 1619 /ANNA R FALKOWITZ/Primary Examiner, Art Unit 1600
Read full office action

Prosecution Timeline

Nov 17, 2022
Application Filed
Jul 11, 2025
Non-Final Rejection — §103
Oct 17, 2025
Response Filed
Jan 14, 2026
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12576046
AQUEOUS PAEDIATRIC RETINOL FORMULATIONS
2y 5m to grant Granted Mar 17, 2026
Patent 12576035
POLYMERIC IMPLANTS WITH HIGH DRUG LOADING AND LONG-ACTING DRUG RELEASE AND METHODS OF MAKING THE SAME
2y 5m to grant Granted Mar 17, 2026
Patent 12576108
COMPOSITIONS COMPRISING HYPER HARMONIZED HYDROXYL MODIFIED FULLERENE SUBSTANCES
2y 5m to grant Granted Mar 17, 2026
Patent 12568972
PYRIDAZINOL COMPOUNDS AND DERIVATIVES, PREPARATION METHODS, HERBICIDAL COMPOSITIONS AND APPLICATIONS THEREOF
2y 5m to grant Granted Mar 10, 2026
Patent 12557809
WOOD PRESERVATIVES
2y 5m to grant Granted Feb 24, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

3-4
Expected OA Rounds
31%
Grant Probability
94%
With Interview (+62.8%)
3y 10m
Median Time to Grant
Moderate
PTA Risk
Based on 90 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month