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 .
Status of the Claims
Claims 1-2 and 4-16, 18-19, 21-23, and 25 are currently pending.
Claim 1, 13, 14, 16, 19 are amended.
Claim 18 has been withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Invention, there being no allowable generic or linking claim.
Claim 3, 17, 20, and 24 are cancelled.
Claim 25 is newly added.
Claims 1-2, 4-16, 19, 21-23, and 25 have been considered on the merits.
Withdrawn Rejections
The objections made onto claims 13, 14, and 16, are withdrawn in light of the amendments submitted on 08/04/2025.
The rejection made onto claims 17, 20, and 24 under 35 U.S.C. 101 is withdrawn in light of the amendments submitted on 08/04/2025.
New and Maintained Rejections Necessitated by Amendment
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.
Claims 1-2, 4-16, 19, and 21-23 are rejected under 35 U.S.C. 103 as being unpatentable over Ashton et al (US20190024046A1) (reference of record), in view of Smirnov et al (Biomaterials, 2014).
With regards to claims 1 and 19, Ashton teaches a method of producing a biomimetic neuroepithelial tissue having a singular rosette structure as required by claim 19 ([0006]). The method is taught to comprise the steps as follows:
Step a comprises seeding the hPSCs with rho kinase inhibitor on a micropatterned substrate that instructs biomimetic neural morphogenesis of the cells as required by claims 1 and 19; ([0006]);
Step b comprises culturing the cells for 1-2 days using a pluripotency maintenance medium which contains a rho kinase inhibitor as required by claims 1 and 19 ([0006]);
Step c comprises a second culture period of 3-6 days under adherent culture conditions in neural differentiation medium as required by claims 1 and 19 ([0006]).
Ashton also teaches wherein the micropatterned substrate is two circular bounded regions, which can have a diameter of 150-800 um as required by claims 1 and 2 ([0008]). Ashton also teaches that the tissue with the desired rosette structure is obtained and comprises polarized neuroepithelial cells and has a microscale cellular organization similar to that of a traverse section of in vivo developing human neural tube as required by claims 17, 20, and 24 ([0006]). Ashton teaches that the hPSCs are seeded at a density of 75 x 103 to 2.5 x 105 cells/cm2 as required by claim 4 ([0007]). The pluripotency medium is taught to contain DMEM/F-12, ascorbic acid, sodium bicarbonate, selenium, insulin, transferrin, FGF2 and TGFB1 as required by claim 5 ([0007]). Ashton also teaches that the pluripotency medium is E8 medium as required by claim 6 ([0054]). The neural differentiation medium is taught to contain DMEM/F-12, ascorbic acid, sodium bicarbonate, selenium, insulin, and transferrin as required by claim 7 ([0007]). The neural differentiation medium is taught to be E6 medium as required by claim 8 ([0054]). Further, the neural differentiation medium contains FGF with or without a beta-catenin activator, which could be FGF2, FGF8a, FGF8b, FGF8f, FGF17 or FGF18 as required by claims 5, 9 and 10 ([0054]). The beta-catenin activator is a GSK3 kinase activator, more specifically CHIR99021 as required by claims 11 and 12 ([0054]). The method also comprises transiently exposing cells on the micropatterned substrate to an activator of wnt/ beta-catenin for about 24-72 hours after plating as required by claim 13 ([0006]). The method further comprises exposing the seeded cells to RA and SHH or an SHH agonist for about 1-5 days, where the rosette structure comprises oligo2+ motor neuron progenitors as required by claim 14 ([0006]). The cells are exposed to RA/SHH/SHH agonist for about 24-72 hours as required by claim 22 ([0006]). The micropatterned substrate comprises a singular or plurality of PEG brushes of peptide-immobilizing PEG brushes arranged in a user defined, bounded geometry as required by claim 15 ([0008]). The method further comprises overlaying the neuroepithelial tissue obtained in step c with a hydrogel layer and culturing the neuroepithelial tissue comprising the hydrogel layer, taught to be Matrigel, where the tissue morphs into a bioengineered neuroepithelial tube and becomes encased in the hydrogel layer as required by claim 16 and 19 ([0131]). The neuroepithelial tissue and the hydrogel layer is cultured for about 24 hours and then removed as required by claim 19 and 23 ([0143]).
Ashton does not teach that the micropatterned substrate comprises at least two circular regions bound through a connection by a cell-adhesive bridge having a length between 25-125 um and a width of about 10-100 um as required by claim 1, 19, and 21.
However, Ashton does describe a micropatterned substrate that comprises regions that promote adherence of cells cultured there on as required by claims 1 and 21 ([0062]). Ashton further teaches that the “bounded geometric shape can be any two-dimensional (2-D) shape (e.g., regular or irregular) having dimensions defined by the shape (e.g., pre-defined diameter, length, width etc.) (e.g., diameter, width, length and the like). In some embodiments, the bounded geometric shapes are circle, triangles, squares, rectangles, or ovals of varying dimensions (e.g., 36 μm, 100 μm, 490 μm, 4.8 mm, and 12.6 mm in diameter; typically about 200-800 μm).” ([0062]). Further, Ashton teaches that both the length and width of the entire shape is between 100-800 um ([0062]).
Additionally, Smirnov teaches the effects of confinement to particular micropatterned substrates on neuron growth cone morphology (abstract). Smirnov teaches a series of bounded/interconnected circular/elliptical geometries which are connected through a channel (i.e. bridge) (Fig. 1). Smirnov teaches that the channel/bridge width range from 1.5 to 12 um as required by claim 1 (pg. 6753, para 2). Smirnov teaches that the channel/bridge width of 12 um resulted in a higher growth cone velocity (Fig, 3). Further, Smirnov teaches that the length of the bridge is at least higher than 25 um as required by claim 1 (Fig. 3a).
Regarding the length of the channel, Smirnov teaches that the length of the bridge is at least longer than 25 um and Ashton teaches that both the length and width of the entire shape is between 100-800 um ([0062]). Additionally, Ashton teaches that the “bounded geometric shape can be any two-dimensional (2-D) shape (e.g., regular or irregular) having dimensions defined by the shape (e.g., pre-defined diameter, length, width etc.) (e.g., diameter, width, length and the like). In some embodiments, the bounded geometric shapes are circle, triangles, squares, rectangles, or ovals of varying dimensions (e.g., 36 μm, 100 μm, 490 μm, 4.8 mm, and 12.6 mm in diameter; typically about 200-800 μm).” ([0062]). Therefore, based on both Ashton and Smirnov a person of ordinary skill in the art would easily arrive at a channel length between 25 and 125 um.
One of ordinary skill in the art would find it obvious before the effective filling date of the instant invention to combine the biomimetic neuroepithelial tissue having a singular rosette structure on a micropatterned substrate as taught by Ashton with the micropatterned substrate containing a connecting bridge taught by Smirnov to arrive at the instant invention. One of ordinary skill in the art would be motivated to make this combination because Smirnov teaches that the channel/bridge width of 12 um resulted in a higher growth cone velocity (i.e. faster neurite outgrowth) (Fig. 3). One of ordinary skill in the art would have a reasonable expectation of success when combining Ashton with Smirnov because Ashton teaches all aspects of the growth of the biomimetic neuroepithelial tissue on micropatterned substrate and Smirnov teaches that including a channel/bridge as part of the micropatterned substrate increased speed of neurite growth cone outgrowth (Fig. 3).
Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the effective time of filing of the invention, especially in the absence of evidence to the contrary.
Claims 1 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Ashton et al (US20190024046A1), in view of Smirnov et al (Biomaterials, 2014) (references of record), as applied to claims 1-2, 4-16, 19, and 21-23 above, and in further view of Mahoney
With regards to claim 25, Ashton and Smirnov teach the limitations of the independent claim 1 above.
Ashton and Smirnov do not teach that the cell-adhesive bridge has a width of about 25 𝜇m.
However, as stated above, Smirnov teaches that the channel/bridge width range from 1.5 to 12 um as required by claim 1 (pg. 6753, para 2). Smirnov teaches that the channel/bridge width of 12 um resulted in a higher growth cone velocity (Fig, 3).
Additionally, Mahoney teaches about the influence of microchannels on neurite growth and architecture. Mahoney discloses the use of microchannels which are 20-60 𝜇m, more specifically Mahoney discloses that “[m]icrochannels 20-30 𝜇m wide maybe most useful in directing growth of unipolar and bipolar neurons… wider microchannels may be useful for directing the growth of cells that extend multiple dendrites…[and that their] data suggest that materials with different microstructural features might be useful in encouraging the development of appropriate neuronal architecture” (pg. 777, col. 2, para 2).
The combination of prior art cited above in all rejections under 35 U.S.C. 103 satisfies the factual inquiries as set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966). Once this has been accomplished the holdings in KSR can be applied (KSR International Co. v. Teleflex Inc. (KSR), 550 U.S. ___, 82 USPQ2d 1385 (2007)): "Exemplary rationales that may support a conclusion of obviousness include: (A) Combining prior art elements according to known methods to yield predictable results; (B) Simple substitution of one known element for another to obtain predictable results; (C) Use of known technique to improve similar devices (methods, or products) in the same way; (D) Applying a known technique to a known device (method, or product) ready for improvement to yield predictable results; (E) "Obvious to try" - choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success; (F) Known work in one field of endeavor may prompt variations of it for use in either the same field or a different one based on design incentives or other market forces if the variations are predictable to one of ordinary skill in the art; (G) Some teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art reference or to combine prior art reference teachings to arrive at the claimed invention.
In the present situation, rationales A, E, and G are applicable. The claims merely require the combining of known prior art methods of adjusting microchannel width as taught by both Smirnov and Mahoney. Additionally, Mahoney provides a support and motivation for one of ordinary skill in the art to test and refine the microchannel width for the specific desired outcome by stating: “[m]icrochannels 20-30 𝜇m wide maybe most useful in directing growth of unipolar and bipolar neurons… wider microchannels may be useful for directing the growth of cells that extend multiple dendrites…[and that their] data suggest that materials with different microstructural features might be useful in encouraging the development of appropriate neuronal architecture” (pg. 777, col. 2, para 2). The combination of Smirnov and Mahoney would lead to a predictable result absent results to the contrary. Thus, the teachings of the cited prior art in the obviousness rejection above provide the requisite teachings and motivations with a clear, reasonable expectation. The cited prior art meets the criteria set forth in both Graham and KSR.
Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the effective time of filing of the invention, especially in the absence of evidence to the contrary.
Response to Arguments
Applicant's arguments filed 08/04/2025 have been fully considered but they are not persuasive.
Applicant argues (Remarks, pg. 10, last para spanning pg. 11) that neither Ashton nor Smirnov discloses or suggests the current method, with emphasis on the newly amended claim limitations of “a series of interconnected circular bounded regions”, the result of practicing the method result in “an elongated biomimetic neuroepithelial tissue”, and the newly added claim 25 which limits the width of the bridge to be 25 𝜇m.
This is not found persuasive. Smirnov discloses a series of interconnected circular bound regions in (Fig. 1), which meets the newly amended limitation of claim 1. Additionally, the method results in the formation of an elongated biomimetic neuroepithelial tissue, which is an intended result of the claimed method. Therefore, the combination of Ashton and Smirnov would yield the intended result of an elongated biomimetic neuroepithelial tissue as required by claim 1. Finally, Ashton is not relied upon to teach the limitations of the newly added claim 25, however both Smirnov and Mahoney support that cell bridges/microchannels with widths between about 1.5-60 𝜇m are an “obvious to try” with a reasonable expectation of success. Additionally, Mahoney provides a support and motivation for one of ordinary skill in the art to test and refine the microchannel width for the specific desired outcome by stating: “[m]icrochannels 20-30 𝜇m wide maybe most useful in directing growth of unipolar and bipolar neurons… wider microchannels may be useful for directing the growth of cells that extend multiple dendrites…[and that their] data suggest that materials with different microstructural features might be useful in encouraging the development of appropriate neuronal architecture” (pg. 777, col. 2, para 2). Therefore, the arguments are not found persuasive.
Applicant argues (pg. 12, para 2-3) that there is not a reasonable rationale for combining Ashton and Smirnov and that a skilled person “would not be motivated to combine them because of Smirnov’s ‘higher growth cone velocity’… and that it appears this rejection is based on hindsight”.
This is not found persuasive. In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). Ashton teaches the entire method other than connecting the circular bound regions by a cell-adhesion bridge. Smirnov is only relied upon to teach connecting the circular bound regions by a cell-adhesive bridge and they found that when neurons are grown using a confined bridge in this manner, they experience higher growth cone velocity. One of ordinary skill in the art would find it obvious before the effective filling date of the instant invention to combine the biomimetic neuroepithelial tissue having a singular rosette structure on a micropatterned substrate as taught by Ashton with the micropatterned substrate containing a connecting bridge taught by Smirnov to arrive at the instant invention. One of ordinary skill in the art would be motivated to make this combination because Smirnov teaches that the channel/bridge width of 12 um resulted in a higher growth cone velocity (i.e. faster neurite outgrowth) (Fig. 3). One of ordinary skill in the art would have a reasonable expectation of success when combining Ashton with Smirnov because Ashton teaches all aspects of the growth of the biomimetic neuroepithelial tissue on micropatterned substrate and Smirnov teaches that including a channel/bridge as part of the micropatterned substrate increased speed of neurite growth cone outgrowth (Fig. 3). Therefore, the argument is not found persuasive.
Applicant argues (Remarks, pg. 12, last para spanning pg. 13) that a reasonable expectation of success for arriving at the instant claims and that “the Action provides no rationale for why a skilled person should reasonably expect to obtain ‘an elongated bioengineered neuroepithelial tissue having a singular polarized rosette structure that spans the length of the tissue”.
This is not found persuasive. The method of claim 1 results in the formation of an elongated biomimetic neuroepithelial tissue and the method of claim 19 results in the formation of an elongated bioengineered neuroepithelial tissue, which are intended results of the claimed methods. Therefore, the combination of Ashton and Smirnov would yield the intended result of an elongated biomimetic/bioengineered neuroepithelial tissue as required by claims 1 and 19. Additionally, One of ordinary skill in the art would have a reasonable expectation of success when combining Ashton with Smirnov because Ashton teaches all aspects of the growth of the biomimetic neuroepithelial tissue on micropatterned substrate and Smirnov teaches that including a channel/bridge as part of the micropatterned substrate increased speed of neurite growth cone outgrowth (Fig. 3). Therefore, the argument is not found persuasive.
Conclusion
No claims are allowed.
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 CONSTANTINA E STAVROU whose telephone number is (571)272-9899. The examiner can normally be reached M-F 8:00-5:00.
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CONSTANTINA E. STAVROU
Examiner
Art Unit 1632
/ANOOP K SINGH/Primary Examiner, Art Unit 1632