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 .
Claims 1, 5, and 8-12 are pending. All have been examined on the merits.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 11/26/2025 has been entered.
Claims 1, 5, and 8 were amended in the claimset dated 11/26/2025.
Claims 4 and 7 were cancelled in the claimset dated 11/26/2025.
Accordingly, claims 1, 5, and 8-12 are pending and under consideration.
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, 5, and 8-12 are rejected under 35 U.S.C. 103 as being unpatentable over Thermofisher (of record) in view of Ryu et al. (Polydopamine Surface Chemistry: A Decade of Discovery, 2019), Guo et al. (CN 109321513 A), Xu et al. (Polydopamine-induced hydroxyapatite coating facilities hydroxyapatite/polyamide 66 implant osteogenesis: an in vitro and in vivo evaluation, 2018), and Sarrigiannidis et al. (A tough act to follow: collagen hydrogel modifications to improve mechanical and growth factor loading capabilities, 2021)
Regarding Claim 1: Claim 1 teaches a method of producing reconstructed human skin in a culture vessel comprising an inner chamber surrounded by an outer wall which the inner vessel has a porous bottom and is spaced apart and surrounded by the outer chamber. There is also an adhesive layer coating the inner wall of the inner vessel. Thermofisher teaches a method of culturing human epidermal keratinocytes as described above which includes a culture vessel with an inner porous insert, coated with an adhesive layer, and culturing human epidermal keratinocytes on said adhesive layer. Thermofisher fails to teach use of dopamine to coat the inner wall of the inner chamber at a concentration of 0.1-20 mg/mL which reacts for 1-3 hours, or forming a 3D hydrogel scaffold matrix by placing a collagen type 1 solution into the inner chamber and gelling the scaffold mixture.
Ryu teaches the history of polydopamine surface chemistry, including the method of dissolving dopamine hydrochloride at a concentration of <0.5 mg/mL but up to 5 mg/mL in a solvent such as Tris at a pH of 8.0-8.5 for a time period of 1-3 hours, noting that timepoint is necessary to help eliminate surface roughness. (pg 6, 4.1) This reads on the method of claim 1 regarding use of a dopamine coating solution at a concentration of between 0.1-20 mg/mL which is allowed to react for 1 to 3 hours. Ryu further teaches that polydopamine (which is the resulting product from dissolving dopamine hydrochloride in a buffering solution) is useful for cell culture regarding stem cell and differentiated cell culture (pg 5, section 3) and that polydopamine is one of the simplest and most versatile approaches to functionalizing material surfaces. (Pg 1, Abstract) Ryu fails to teach use of a collagen type I hydrogel scaffold that is gelled into the inner chamber of the culture vessel.
Sarrigiannidis teaches that collagen hydrogels are among the most well-studied platforms for drug delivery and tissue engineering due to being low cost, low immunogenicity, versatile, having a high degree of biocompatibility, and being similar to naturally occurring ECM. However, by themselves, collagen hydrogels have a relatively low degree of mechanical properties when not cross-linked. (Pg 1, Abstract). Specifically, Sarrigiannidis teaches several methods of cross-linking collagen 1 by means of physically cross-linking, chemical cross-linking, and enzymatic cross-linking. (Pg. 3-11, 2.1) It would have been obvious to a person of ordinary skill in the art to incorporate the teachings of Sarrigiannidis with the teachings of Ryu to create a gelled three-dimensional hydrogel scaffold due to the benefits of cross-linking type 1 collagen hydrogels resulting in a greater degree of mechanical properties and that collagen hydrogels are one of the most well-studied platforms in the art for tissue engineering, as taught by Sarrigiannidis. (Pg 1, Abstract) An example of the gelling process for collagen type I is shown below, taken from pg. 2, fig 1:
PNG
media_image1.png
948
1020
media_image1.png
Greyscale
Regarding Claim 5: The protocol by Thermofisher teaches a method for culturing human epidermal keratinocytes as described above. While Thermofisher does not teach use of Tris-HCl as a solvent with a pH range of 8.0-9.0, Xu teaches a method of coating of a polydopamine film using 2mg/mL dopamine dissolved in Tris-HCL buffer at a pH of 8.5 and that it is universally agreed upon that use of the concentration of 2 mg/mL dopamine dissolved in Tris-HCL at a pH of 8.5 is the best method of preparation. (Pg 8188, Discussion) In addition to this, Ryu teaches the benefits of use of dopamine hydrochloride to form polydopamine to be used in coating applications for a wide variety of tasks, including cell culture (as discussed above). The pH range of 8-8.5 falls within the claimed range of 8.0-9.0. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the culture protocol taught by Thermofisher with the buffer solution and pH range taught by Xu et. al to use Tris-HCl at a pH of 8.0 to 9.0. One of ordinary skill in the art would recognize the Thermofisher protocol could be performed with any buffer solution and would choose a buffer appropriate for the desired pH range, and the teachings of Ryu of polydopamine being simple and versatile to use in cell culture would give a person of ordinary skill in the art motivation to incorporate it into the teachings of Thermofisher and Xu.
Regarding Claim 8: Guo et al. teaches mixing dermal fibroblasts with type 1 collagen solution and Dulbecco’s Modified Eagle’s medium to create a seeded scaffold, which has useful applications for wound recovery and promotes hair generation. (Pg. 1, Abstract)
Regarding Claim 9: Claim 9 teaches use of a basement membrane component material. It is known throughout the art that type I collagen is a known component of the basement membrane.
Regarding Claim 10: Thermofisher teaches that the “cells were seeded with 0.5mL of growth medium…into the upper compartment”. One of ordinary skill in the art would recognize this to mean that the protocol by thermofisher teaches seeding epidermal keratinocytes into the insert component of their culture well, which is surrounded by the outer wall of the outer compartment.
Regarding Claim 11: The protocol as taught by Thermofisher teaches supplying growth media into the “lower and upper” compartments upon seeding the porous insert with epidermal keratinocytes. (Thermofisher, Page 2, “Air-Liquid Interface Culture on Inserts”) As illustrated by Fig. 4 on page 4, it can be seen that the porous insert (referred to as “upper”) is inside and surrounded by the well plate (referred to as “lower”). Therefore, Thermofisher teaches an inner porous well surrounded by an outer well.
Regarding Claim 12: The protocol as taught by Thermofisher teaches removing the original media and replacing it only in the “lower” compartment. (Thermofisher, Page 2, “Air-Liquid Interface Culture on Inserts”) As described above, the lower compartment is functionally identical to the outer chamber taught by Claim 12 as referenced by Figure 4 as the lower compartment completely surrounds the upper compartment.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Thermofisher with the teachings of Ryu, Sarrigiannidis, Xu, and Guo to create a method of producing reconstructed human skin using a culture vessel comprising an inner chamber and outer chamber which has been coated with dopamine dissolved in Tris-HCL and collagen I which has been gelled upon which human keratinocytes are cultured. A person skilled in the art would have had the following reasons of motivation for combining the teachings set forth above:
Ryu teaches that use of a dopamine coating is useful in cell culture and is a simple and versatile method of functionalizing material surfaces. Therefore, one skilled in the art would be motivated to coat the inner walls of the culture vessel with it.
Sarrigiannidis teaches that cross-linking of collagen hydrogels, specifically collagen type I, results in a greater degree of mechanical properties and that collagen hydrogels are among the most well-studied platforms for tissue engineering, making it an obvious choice for a substrate to be used in cell culture.
Xu teaches that the best universally accepted method of preparation of a polydopamine film is use of 2 mg/mL of dopamine dissolved in Tris-HCL at a pH of 8.5.
Guo teaches that the method of mixing dermal fibroblasts with type 1 collagen solution and Dulbecco’s Modified Eagle’s medium forms a seeded scaffold, which is useful for wound recovery and hair generation.
In combining all of the aforementioned teachings with their respective reasons for motivation, one skilled in the art would arrive at a dual well culture system with a type I collagen (basement membrane component) hydrogel coating comprising dermal fibroblasts and a dopamine coating on the inner wall of the inner culture vessel to encourage cell attachment and achieve culture of a human skin model.
Response to Arguments
Applicant's arguments filed 11/26/2025 have been fully considered but they are not persuasive. Applicant has stated that in the interest of expediting prosecution, the subject matter of claim 3 has been incorporated into claim 1 and therefore is not anticipated by the combination of Thermofisher and Wen and since claims 5, 11, and 12 depend on claim 1, they should be considered allowable for at least that same reason. As necessitated by amendment, the teachings of Ryu, Guo, Xu, and Sarrigiannidis have been incorporated into the rejection through U.S.C. 103 and now read on the amended claim 1 for the following reasons:
Ryu teaches that dopamine is useful in cell culture due to it being a simple and versatile method of functionalizing material surfaces, giving a person of ordinary skill in the art motivation to use it to coat the surface of the inner wall in the chamber and teaches a protocol of dissolving dopamine hydrochloride at a concentration of <0.5 mg/mL but up to 5 mg/mL in a solvent such as Tris at a pH of 8.0-8.5 for a time period of 1-3 hours, reading on the claimed concentration and time range.
Sarrigiannidis teaches the usefulness of cross-linking collagen type 1 hydrogels and how it increases their mechanical properties, in addition to them being well-studied in the art, making it an obvious choice for a substrate to be used in tissue engineering. This gives one skilled in the art motivation to incorporate it as a cross-linked hydrogel into the culture system of claim 1.
Xu teaches that the most universally accepted method of preparation of a polydopamine film to be used in coating application sis 2 mg/mL of dopamine hydrochloride dissolved in Tris-HCL at a pH of 8.5, giving a person skilled in the art motivation and a reasonable expectation of success at incorporating a dopamine coating into the claimed culture system at the claimed concentration and with Tris-HCL.
Guo teaches that the mixing of dermal fibroblasts with a type 1 collagen solution to create a seeded scaffold is useful in wound recovery, which gives a person of ordinary skill in the art motivation to incorporate a seeded scaffold into the claimed culture system.
For the above reasons, the arguments regarding claim 1 are unpersuasive.
Furthermore, the central argument presented by the Applicant is that there would be no motivation to use dopamine to coat the surface of the inner wall surrounding the inner chamber. However, as discussed above, Ryu teaches that use of a dopamine coating is known to be a simple and versatile method of functionalizing material surfaces and Xu teaches that the most universally accepted method of preparation of a polydopamine film is to use dopamine hydrochloride dissolved in Tris-HCL at the claimed concentration. These teachings combined with the dual well porous culture system as taught by Thermofisher would give motivation to a person of ordinary skill in the art to create a 3D culture system for reconstructed human skin comprising coating the inner chamber wall with dopamine, coating the inner chamber bottom well surface with collagen type 1 which has been gelled, and seeding epidermal keratinocytes on said hydrogel surface.
Applicant further argues that the teachings of Thermofisher, Wen, LKT, and Xu fail to read on use of the dopamine coating solution on the surface of the inner wall being allowed to react for 1-3 hours. While Xu discloses that the dopamine solution was immersed in the 2 mg/mL substrate for 24 hours, the teachings of Ryu (which, as necessitated by amendment, now are incorporated for the rejection of the amended claim 1) state that dissolving dopamine hydrochloride at a concentration of <0.5 mg/mL but up to 5 mg/mL in a solvent such as Tris at a pH of 8.0-8.5 for a time period of 1-3 hours, noting that timepoint is necessary to help eliminate surface roughness after coating.
Applicant further argues that the combination of the teachings of Thermofisher, Wen, Cascade, and Guo fail to disclose or suggest placing a scaffold solution comprising a type 1 collagen solution in the inner chamber and performing gelling. However, as necessitated by amendment, the teachings of Sarrigiannidis of the benefit of cross-linking type 1 collagen hydrogels results in a greater degree of mechanical properties and that collagen hydrogels are one of the most well-studied platforms for tissue engineering have been incorporated in to the rejection of the claims. In addition to this, Thermofisher teaches the culture of human epidermal keratinocytes on the inner surface of the inner porous chamber of the dual culture system. One of ordinary skill in the art would have been motivated to combine the teachings of Sarrigiannidis with the teachings of Thermofisher to incorporate a type 1 collagen hydrogel on which to culture the human epidermal keratinocytes due to Sarrigiannidis stating that cross-linking aids in the mechanical properties of collagen 1 and that collagen 1 hydrogels are among the most well-studied platforms for tissue engineering.
Based on the above discussion, the arguments presented by the Applicant are unpersuasive and the rejections of claims 1, 5, and 8-12 are upheld.
Conclusion
Any inquiry concerning this communication or earlier communications from the
examiner should be directed to HANNA M THUESON whose telephone number is (571) 272-
3680. The examiner can normally be reached M-F 7:30-5 EST.
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, Tracy Vivlemore, can be reached on (571) 272-2914. 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
/HANNA MARIE THUESON/Examiner, Art Unit 1638
/Tracy Vivlemore/Supervisory Primary Examiner, Art Unit 1638