DETAILED ACTION
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.
Claims 1, 3 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Aratani (US 20190309257) in view of Nakazawa (US 20080138900) and Makino (US 20170175078).
With respect to claim 1, Aratani discloses a cell culture sheet comprising a plurality of recesses (7:120) having an inner face defined by a structural layer (Figure 7:110) having an inner circumferential face and a bottom face defined by a base layer (Figure 7:130). Aratani discloses in paragraphs [0067]-[0071] that the inner circumferential face has a non-cell-adhesive surface. Paragraphs [0073] and [0074] teach that the bottom face has a cell-adhesive surface (Figure 7:B) comprising collagen, fibronectin and laminin. Paragraphs [0065] and [0071] additionally state that the bottom face includes a polyimide resin composition (“The constituent material of the base material is not particularly limited…Examples of the constituent material include organic materials and inorganic materials described below. One of these constituent materials may be used alone or two or more of these constituent materials may be used in combination” and “Examples of the organic materials include…polyimide”). Paragraph [0174] states that the cell-adhesive surface is substantially 100% of the area of the bottom face of the recess (“seeding the cell adhesive material over the entire surface”). Aratani further teaches in paragraph [0193] that each having an opening of 1,000 microns or less in diameter. Paragraph [0095] and Figure 14 teach that the recesses may be formed in a shape tapered to the bottom face. Paragraphs [0008], [0033], [0062] and [0090] further indicate that the cell culture sheet is a laminate comprising a layer having the non-cell adhesive surface 110 and a layer having the cell-adhesive surface 130, wherein the layer 110 having the non-cell adhesive surface has through-holes (see Figs. 7-9B) (“the member for containing cells of the present disclosure is produced by laminating a structural layer, which is obtained by forming a plurality of holes in a layer formed of a cell non-adhesive material, over a plane of a base material having at least the plane”).
Aratani discloses in paragraphs [0067]-[0071] that the inner circumferential face has a non-cell-adhesive surface made from a variety of different materials, however Aratani does not expressly disclose materials from the claimed group.
Nakazawa discloses a cell culture sheet comprising a plurality of recesses (Figure 2:12). Each recess has an inner circumferential face (Figure 3:22) and a bottom face, wherein the inner circumferential face has a non-cell-adhesive surface and the bottom face has a cell-adhesive surface (Figure 3:30). This is taught in paragraphs [0022]-[0037]. Nakazawa states in paragraph [0045] that polyethylene glycol, MPC, poly-HEMA and SPC or the like are typically used to create non-cell-adhesive surfaces.
Before the effective filing date of the claim invention, it would have been obvious to use polyethylene glycol, MPC, poly-HEMA and SPC or the like when fabricating the inner circumferential face of Aratani. Aratani teaches that “cell non-adhesive material is not particularly limited and may be appropriately selected depending on the intended purpose”. Nakazawa states that polyethylene glycol, MPC, poly-HEMA and SPC materials are well known in the art and especially suitable for creating biological assays and are characterized as having poor cellular adhesiveness.
As stated above, Aratani teaches in paragraphs [0065] and [0071] that the bottom face includes a polyimide resin composition. Aratani, however, does not specifically state that the polyimide resin is a fluorine-containing polyimide resin.
Makino discloses a cell culture container equipped with a cell culture substrate (Figure 5:10) that forms the bottom of the container and a wall member (Figure 5:20) that stands up from the edge of the cell culture substrate. This is described in paragraph [0506]. Each recess has an inner circumferential face and a bottom face (Fig. 5). The cells are cultured on the surface of the base material (bottom face) which has a fluorine containing polyimide (cell-adhesive surface) (paragraph [0024]). The cell culture substrate 10 that forms the bottom of the container and a wall member 20 that stands up from the edge (lines 2921-2923) and the surface of the base material has a polyimide (cell-adhesive surface) (lines 195-197). This results in a laminate with a layer of non-cell adhesive surface (20) and a layer of cell-adhesive surface (10), the non-cell adhesive surface (20) having the through holes (see Fig. 5, above).
Before the effective filing date of the claimed invention, it would have been obvious to modify the Aratani device to include a cell adhesive substance that is a fluorine-containing polyimide resin. Makino indicates that fluorine-containing polyimide resin are especially well suited for the culture of adherent cells because they enable improved development of three-dimensional tissue (“cell growth and formation of three-dimensional tissue, such as a spheroid or three-dimensional cell aggregate, are likely to proceed. When cell culture is conducted while bringing cells and a medium into contact with the polyimide-containing surface of the substrate and bringing oxygen-containing gas such as air into contact with the other surface of the substrate, in addition to with the upper surface of the medium, cell growth and formation of three-dimensional tissue, such as a spheroid or three-dimensional cell aggregate, are likely to proceed”, paragraph [0073]). Makino states that fluorine-containing polyimide resins are characterized by improved cell adherent qualities and oxygen permeability.
With respect to claim 3, Aratani, Nakazawa and Makino disclose the combination as described above. Aratani further teaches that an adhesive layer configured as a masking tape is disposed between the two layers of the laminated structure. See paragraph [0090] (“Examples of the laminated structure include a structure with a masking tape laminated. In this case, the masking tape is not particularly limited and may be appropriately selected depending on the intended purpose. A masking tape having a thin tackifier layer and a weak tackifying force is preferable. When a masking tape has a thin tackifier layer and a weak tackifying force, there is an advantage that when the laminated masking tape is machined with a laser to open holes, the wall surfaces of the holes are less likely to be sticky with the tackifier layer. The material of the masking tape is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the material of the masking tape include polyethylene”)
With respect to claim 7, Aratani, Nakazawa and Makino disclose the combination as described above. Nakazawa teaches in paragraphs [0031] and [0059] that each recess may be approximately 400 microns in diameter, thereby enabling 10 to 1,000 recesses to be formed on a surface of the sheet per cm2. Aratani additionally describes in paragraph [0193] dimensions that enable the formation of a plurality of recesses at 10 to 1,000 per cm2.
Response to Arguments
In response to Applicant’s amendment filed 18 March 2026, the previous rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of the combination of Aratani with Nakazawa and Makino.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NATHAN ANDREW BOWERS whose telephone number is (571)272-8613. The examiner can normally be reached M-F 7am-5pm.
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/NATHAN A BOWERS/ Primary Examiner, Art Unit 1799
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