Indee. Inc.Download PDFPatent Trials and Appeals BoardSep 27, 20212021005157 (P.T.A.B. Sep. 27, 2021) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 15/497,122 04/25/2017 Ryan Pawell IND3-002-010US 3987 127866 7590 09/27/2021 Southern Cross Intellectual Property PO Box 906 Brisbane QLD, 4001 AUSTRALIA EXAMINER POPA, ILEANA ART UNIT PAPER NUMBER 1633 NOTIFICATION DATE DELIVERY MODE 09/27/2021 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): docketing@martinip.com tmartin@martinip.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE __________ BEFORE THE PATENT TRIAL AND APPEAL BOARD __________ Ex parte RYAN PAWELL __________ Appeal 2021-005157 Application 15/497,122 Technology Center 1600 __________ Before JEFFREY N. FREDMAN, CYNTHIA M. HARDMAN, and JAMIE T. WISZ, Administrative Patent Judges. FREDMAN, Administrative Patent Judge. DECISION ON APPEAL This is an appeal1 under 35 U.S.C. § 134 involving claims to a method for introducing an exogenous material into a cell. The Examiner rejected the claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We reverse. 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies the Real Party in Interest as lndee. Inc. (see Appeal Br. 2). We have considered the Specification of April 25, 2017 (“Spec.”); Final Office Action of Nov. 19, 2020 (“Final Action”); Appeal Brief of Jan. 13, 2021 (“Appeal Br.”); Examiner’s Answer of June 29, 2021 (“Ans.”); and Reply Brief of Aug. 26, 2021 (“Reply Br.”). Appeal 2021-005157 Application 15/497,122 2 Statement of the Case Background “[T]he ability to introduce exogenous material and in particular nucleic acids into cells in a quick and efficient manner is both a valuable research tool and a useful component of a therapeutic strategy” (Spec. ¶ 7). “[T]he introduction of agents such as nucleic acids into eukaryotic cells is generally referred to as ‘transfection’, whereas the introduction of nucleic acid into prokaryotic cells is generally referred to as ‘transformation’. Transfection and transformation methods may be conveniently separated into three categories, namely, chemical, physical and viral-based methods” (id. ¶ 9). The Specification teaches “[i]t has been surprisingly found by the inventor that, when exposed to a transient decrease in pressure, cells are susceptible to the uptake of exogenous material” (Spec. ¶ 18). “A relatively sudden and temporary pressure drop across the cell membrane, whereby the intracellular pressure is greater than the extracellular pressure, may result in the temporary formation of pores in the membrane allowing for the introduction of the exogenous material” (id. ¶ 19). The Claims Claims 1, 2, 4–7, 17, and 21–43 are on appeal. Claim 1 is an independent claim, is representative and reads as follows: 1. A method for introducing an exogenous material into a cell, comprising: introducing a liquid including the cell and the exogenous material into a flow channel of a microfluidic device, the channel including at least two flow diverters, the gap between the at least two flow diverters having a width, the width of the gap being greater than the diameter of the cell; and Appeal 2021-005157 Application 15/497,122 3 exposing said cell to a transient decrease in pressure and unsteady flow downstream of the flow diverters when the cell flows past the flow diverters to thereby introduce said exogenous material into said cell. The Rejections A. The Examiner rejected claims 1, 2, 4–7, 17, 22–33, and 36–43 under 35 U.S.C. § 103(a) as obvious over Sharei,2 Clarke,3 Doranz,4 and Hans5 (Final Act. 2–5). B. The Examiner rejected claims 1, 2, 4–7, 17, 21–33, and 36–43 under 35 U.S.C. § 103(a) as obvious over Sharei, Clarke, Doranz, Hans, and Diefenbach6 (Final Act. 5–6). C. The Examiner rejected claims 1, 2, 4–7, 17, and 22–43 under 35 U.S.C. § 103(a) as obvious over Sharei, Clarke, Doranz, Hans, and Hejna7 (Final Act. 6–7). A. 35 U.S.C. § 103(a) over Sharei, Clarke, Doranz, and Hans The Examiner finds Sharei teaches a microfluidic method for the intracellular delivery of an exogenous macromolecule, the method comprising passing a fluid comprising cells and the macromolecule to be delivered 2 Sharei et al., A vector-free microfluidic platform for intracellular delivery, 110 Proc. Nat’l Acad. Sci. USA 2082–87 (2013). 3 Clarke et al., US 8,529,026 B2, issued Sept. 10, 2013 4 Doranz et al., US 2005/0123563 A1, published June 9, 2005. 5 Hans et al., Comparison of pressure and ultrasound measurements in vortex flow meters, 33 Measurement 121–33 (2003). 6 Diefenbach, T., US 2012/0064518 A1, published Mar. 15, 2012. 7 Hejna et al., Functional complementation by electroporation of human BACs into mammalian fibroblast cells, 26 Nucleic Acids Res. 1124–5 (1998). Appeal 2021-005157 Application 15/497,122 4 through an enclosed microchannel comprising at least one constriction (i.e., obstacle) having a dimension smaller than the cell diameter to induce transient holes into the cell membrane and introduce the macromolecule and siRNAs into the cell cytoplasm. (Final Act. 3). The Examiner acknowledges that Sharei does “not specifically teach unsteady flow around the flow diverter, nor do they teach a transitional vortex street” (id.). The Examiner finds “modifying the method of Sharei [] by using obstacles resulting in a vortex street is suggested by the prior art” because Clarke teaches “bluff bodies or pillars (such as cylinders) placed within a microchannel could be used to create unsteady flow such (as a vortex street) in the microchannel” and Doranz teaches “vortices can be used to create transient holes in lipid membranes” (Final Act. 3). The Examiner finds Hans evidences that “vortex structures are areas of lower pressure than the surrounding liquid” (id. at 3–4). The Examiner finds it obvious to combine “to achieve the predictable result of introducing macromolecules into cells by creating transient holes into the cell membrane via a vortex street. By doing so, one of skill in the art would have used a microfluidic device comprising at least two flow diverters separated by gaps” (Final Act. 4). The Examiner finds the ordinary artisan “would have concluded that a gap with a dimension smaller than the cell diameter is not necessary when using a vortex and would have found obvious to use a gap width greater than the cell diameter” (id.). Appellant contends “that for a case involving method claims, motivation is required” (Appeal Br. 8). Appellant specifically contends: Appeal 2021-005157 Application 15/497,122 5 Sharei teaches that a constriction smaller than the cell diameter is necessary to induce transient holes into the cell membrane. Attempting to modify Sharei so that it is actually opposite to what Sharei says is necessary is prima facie hindsight reasoning . . . Additionally, the device of Sharei is optimized for eliminating vortices (Sharei at page 2083, column 1), so attempting to modify the Sharei device and method so that it produces vortices is contrary to one of the key principles underlying Sharei’s design. (id. at 5). Appellant contends “the inkjet technology of Clarke would not have logically commended itself to an inventor’s attention in considering the problem” (id. at 11). Appellant also “disagrees that either Doranz or Clarke alone or together make up for the deficiencies of Sharei, or that it would have been obvious to one skilled in the art to combine these references” (id. at 6). Appellant contends the “circular airflow behind the bluff bodies of Hans are not equivalent to Appellant’s transient decrease in pressure and unsteady flow” (id. at 7). Lastly, Appellant contends that “[w]hen fully and properly considered, the claimed invention shows surprising results, as evidenced by the Di Carlo Declaration” (id. at 12). The issues with respect to this rejection are: (i) Does a preponderance of the evidence of record support the Examiner’s conclusion that the prior art suggests the method of claim 1? (ii) If so, has Appellant provided evidence of unexpected results that outweighs the evidence supporting the prima facie case of obviousness? Findings of Fact 1. Sharei teaches methods “for cytosolic delivery based on rapid mechanical deformation of the cell to produce transient membrane disruptions that facilitate the passive diffusion of material into the cell Appeal 2021-005157 Application 15/497,122 6 cytosol. This method was developed with the aim of delivering almost any macromolecule of interest to almost any cell type, at high throughput” (Sharei 2082, col. 2). 2. Figure 1, panels A and B of Sharei are reproduced below: Fig. 1. Delivery mechanism and system design. (A) Illustration of delivery hypothesis whereby the rapid deformation of a cell, as it passes through a microfluidic constriction, generates transient membrane holes. Includes an electron micrograph of current parallel channel design with blue cells as an illustration. (B) Image of a finished device consisting of Pyrex bound to silicon for sealing. (Sharei 5283, col. 1). 3. Sharei teaches “the rapid mechanical deformation of a cell, as it passes through a constriction with a minimum dimension smaller than the cell diameter, results in the formation of transient membrane disruptions or holes” (Sharei 2082, col. 2). Appeal 2021-005157 Application 15/497,122 7 4. Sharei teaches: We identified cell speed, constriction dimensions, and number of constrictions as three parameters that influence delivery efficiency (defined as the fraction of live cells that receive the delivery material []) by altering the shear and compression rates experienced by the cells. For example, delivery efficiency of membrane-impermeable, Cascade Blue-labeled 3-kDa dextran molecules to live HeLa cells increases monotonically with cell speed across different constriction designs . . . Constriction dimensions also impact delivery; increasing the constriction length from 20 to 40 μm almost doubled delivery efficiency at all operating speeds . . . with minimal effect on viability . . . Decreasing constriction width had a similar effect . . . Increasing the number of constrictions in series also increased delivery efficiency such that a device with five 10-μm length constrictions in series outperformed a single 10-, 20-, or 40-μm length design across all cell speeds. (Sharei 2083, col. 2). 5. Clarke teaches “a device and method for generating droplets of a fluid in a controlled manner with a low range of size dispersity at a rate sufficient for practical commercial use” (Clarke 2:57–60). 6. Clarke teaches flow instability may be caused, for example, by the creation of a series of unsteady eddies within the channel. Preferably, the flow instability is caused by the shedding, preferably periodic or regular, of vortices. Most preferably the flow instability is due to a vortex street in the droplet fluid in the channel. (Clarke 5:38–43). 7. Clarke teaches “perturbation means may include bluff bodies placed within a channel of constant cross-section or it may include changes to the geometry of the channel cross-section, for example constrictions, corners or junctions” (Clarke 6:5–9). Appeal 2021-005157 Application 15/497,122 8 8. Doranz teaches: “Temporary poration or permeabilization can be achieved by such treatments as electroporation, exposure to chemicals or proteins (e.g. streptolysin-O, aerolysin, maltoporin, P2X7, melittin), mechanical stress (e.g. sonication, vortex mixing), and the like” (Doranz ¶ 555). 9. Hans teaches a “vortex structure represents an area of lower pressure and density than in the surrounding fluid” (Hans 122, col. 2). Principles of Law A prima facie case for obviousness “requires a suggestion of all limitations in a claim,” CFMT, Inc. v. Yieldup Int’l Corp., 349 F.3d 1333, 1342 (Fed. Cir. 2003), and “a reason that would have prompted a person of ordinary skill in the relevant field to combine the elements in the way the claimed new invention does.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007). Analysis We do not agree with Appellant that a teaching, suggestion, and motivation test is required to render method claims obvious, instead KSR requires a reason to combine teachings in the prior art. KSR, 550 U.S. at 418. However, we agree with Appellant that the Examiner has not identified a reason to modify the method of Sharei, in which cell constriction is used to introduce material into cell cytosols, with flow diverters having a gap “greater than the diameter of the cell” as required by claim 1. The Examiner acknowledges a “difference between Sharei and the instant invention is that Sharei uses squeezing and not a vortex street to induce the transient holes” (Ans. 9). The Examiner responds that “the prior Appeal 2021-005157 Application 15/497,122 9 art indicates functional equivalency between squeezing and vortices with respect to creating transient holes in cell lipid membranes” (id.). We are not persuaded. Sharei requires a constriction and specifically finds that longer constriction lengths and narrower constrictions resulted in greater delivery efficiency into cells (FF 4). This is the opposite of the requirement of the claim for gaps wider than the cell diameter. Clarke and Hans provide no information regarding delivery of material into cells (FF 5– 7, 9). And we find the Examiner’s reliance on Doranz for vortices particularly unpersuasive, because Doranz is clearly referring to a vortex mixer, a simple common laboratory device used to mix microcentrifuge tubes or other small vials (FF 6). Doranz is not referring to microfluidic devices such as those of Sharei. Doranz does not reasonably suggest that vortices in microfluidic devices are equivalent to constriction in microfluidic devices. Doranz therefore lacks evidence that vortices in microfluidic devices would reasonably be expected to result in the cell poration obtained in Sharei’s device. We therefore agree with Appellant that this rejection relies on hindsight. “We must still be careful not to allow hindsight reconstruction of references to reach the claimed invention without any explanation as to how or why the references would be combined to produce the claimed invention.” Innogenetics, N.V. v. Abbott Labs., 512 F.3d 1363, 1374 n.3 (Fed. Cir. 2008). Because we find that the Examiner did not establish a prima facie case of obviousness, we need not address the arguments regarding secondary considerations. Appeal 2021-005157 Application 15/497,122 10 Conclusion of Law (i) A preponderance of the evidence of record does not support the Examiner’s conclusion that the prior suggests the method of claim 1. (ii) We do not address the secondary consideration evidence. B.–C. 35 U.S.C. § 103(a) Having reversed the obviousness rejection of claim 1 for the reasons given above, we also find that the Examiner does not point to teachings in the additionally cited prior art that provide a reason to modify the device of Sharei to replace a device that constricts cells with a device that has wider gaps and creates vortices. We therefore reverse these rejections for the same reasons as given above. DECISION SUMMARY In summary: Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1, 2, 4–7, 17, 22–33, 36–43 103 Sharei, Clarke, Doranz, Hans 1, 2, 4–7, 17, 22–33, 36–43 1, 2, 4–7, 17, 21–33, 36–43 103 Sharei, Clarke, Doranz, Hans, Diefenbach 1, 2, 4–7, 17, 21–33, 36–43 1, 2, 4–7, 17, 22–43 103 Sharei, Clarke, Doranz, Hans, Hejna 1, 2, 4–7, 17, 22–43 Overall Outcome 1, 2, 4–7, 17, 21–43 REVERSED Copy with citationCopy as parenthetical citation