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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 8 Jan. 2026 has been entered.
Claims 129-147 and 149 are currently pending and are considered here.
Any rejection not reiterated herein has been withdrawn.
Response to Arguments
Applicant's arguments filed 8 Jan. 2026 have been fully considered but they are not persuasive.
Applicant further argues that one of ordinary skill could readily determine whether a particular device falls within the scope of the claims by examining the surface structure of the particles within the filter. This is not persuasive because, as set forth in the rejection below, the effect of any particular device on cell lysis would depend on a host of undefined factors such that it would not be possible to conclusively ascertain whether the device falls within or outside the scope of the claims (e.g., any column of porous particles could be capable of lysing some types of cells under some conditions while having no effect on other types of cells under other conditions, making it unclear whether such a column falls within the scope of the claims).
Applicant further argues that claims 138-139 are definite because one of ordinary skill could determine whether a filter met the claim limitations by simply introducing a particular cell type to the filter and then measuring the effect of the filter on the cell. This is not persuasive for the same reasons as above – i.e. the effect of any particular device on cell lysis would depend on a host of undefined factors. For example, Fig. 3 of Hu evidences that the degree of lysis varies significantly with contact time, and Michalska evidences that bacterial species having different physiological features (e.g., cell stiffness) have significantly different cell killing responses to nanotextured surfaces.
The indefiniteness rejection could be addressed by amending the claims to further specify the structural features of the claimed particles and/or the filter configuration that correspond with the claimed function. As set forth in the Office Action of 8 Sept. 2025, the claims recite the various surface structures of the particles at such a broad level that they do not provide a clear-cut indication of the scope of the claims (the "pores, pits, craters, nanowires, cones, pinnacles, hoodoos, coral, cords, walls, fins, ridges, crags, pyramids, and inverted pyramids" are defined so broadly in the specification as to encompass essentially any topographical feature(s)).
Claim Rejections - 35 USC § 112(b) (indefiniteness)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 129-147 and 149 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 129 recites “a filter configured to lyse a cell” comprising a chamber containing surface etched powder particles with an inlet and an outlet, wherein “when passing a composition comprising the cell through the filter from the inlet to the outlet, the one or more of the plurality of surface etched powder particles contacts the cell, thereby lysing the cell by physical interaction of the cell with the structure … of the plurality of surface etched powder particles”. The above limitation is indefinite because it defines one or more claim elements (e.g., the nature and/or configuration of the particles/filter) by reference to another element which is undefined and/or variable (the effect of the particles on a cell) (see MPEP 2173.05(b)). The effect of the claimed particles on a cell would be expected to vary based on a number of variable which are undefined in the claims, including the type of cell (e.g., whether it is a mammalian cell, a bacterial cell, a cell with a cell wall, etc.), the conditions under which the cell is passed through the chamber (e.g., pressure, temperature, shear, contact time, etc.) and combinations thereof. For example, Rabolli et al., Nanotoxicology 4.3 (2010): 307-318 (previously cited), evidences that the cytotoxic effect of silica nanoparticles varies between different human cell types, with different physiochemical parameters effecting the different cell types in a different manner (Rabolli, entire doc, including Abstract). Similarly, Michalska et al., Nanoscale 10.14 (2018): 6639-6650, evidences that the cell killing efficacy of nanopillar surfaces varies significantly between different bacterial species (Michalska, under 3.4 Topographies versus various bacterial species; also, under 4. Conclusions – “the rate of killing by a selected surface is dictated by the properties of the bacterial cell (e.g., nature of the cell wall, peptidoglycan layer, and outer membrane; abundance and localization of flagella; extent and composition of secreted polysaccharides, etc.”)). Moreover, Hu et al., Applied physics letters 111.25 (2017), evidences that the degree of cell killing by a nanopillar surface significantly changes with contact time (Hu, Fig. 3). In light of the above, one of ordinary skill in the art presented with a particle-filled chamber according to the claims would not reasonably be able to ascertain whether such a device meets the claim limitation of being capable of lysing a cell, as doing so would require assessing a myriad of potential factors that are undefined by the claims (e.g., all possible cell types and conditions). The limitations of claims 138-139 (wherein the filter lyses a certain % of the cells in a population) would be further indefinite for the reasons set forth above (a skilled artisan would not be reasonably able to determine whether the limitation was met for an undefined population of cells under undefined conditions).
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.
Claims 129-147 and 149 are rejected under 35 U.S.C. 103 as being unpatentable over US201301227717 to Green et al., as evidenced by Hu et al., Applied physics letters 111.25 (2017).
Regarding claims 129, 132, 133, 140-142 and 149, Green teaches surface etched, crystalline or semi-crystalline silicon powder particles that are etched such that the surfaces of each particle comprise nanopillars/nanospikes ([0026]-[0081]; [0090]-[0112]; Examples). Green teaches that the “pillars” are “an elongate structure selected from but not limited to the group comprising rods, columns, nanowires, tubes, fibres, ribbons and flakes and these terms may be used interchangeably herein. A pillar can have a uniform or non-uniform cross section along its length and a circular or non-circular cross-section and can comprise a clump of elongate structures fused or combined together. The diameter or width of a pillar can vary along its length. The pillar can be formed upright or at an angle to a substrate and can have a kink or one or more changes of direction along its length, for example it can form a zig-zag or spiral shape. Pillars can have smooth or rough surfaces and can be micro or macro porous.” ([0028]). Green further teaches that the pillars can have an aspect ratio (height/base diameter) of 5:1 to 100:1 ([0107]). The instant specification states that the terms nanowires, pinnacles and pillars are used interchangeably, and refer to any elongated structure that extends outward from the powder particle including those having a height-to-diameter ratio (aspect ratio) of 2 or more (Published Spec. US20250034398, [0083]). The specification further states that i) “[p]its, craters, pores refer to indentations on the powder particle. Pits and craters may have a depth-to-diameter ratio of less than 2. The term pore is used to refer to any indentation with a depth-to-diameter ratio of 2 or more” (Spec., [0082]); and ii) “any extending structure whose morphology is irregular or whose shape is not geometric ... Any nano- or micro-structure that cannot be easily classified among other classes of structures may be considered a coral” (Spec., [0091]). Thus, the pillars of Green (which can be porous) can be considered as having structures including at least nanowires, pinnacles, corals and pores/pits/craters. Green teaches that the particles can have a size of about 3-100 µm diameter, with pillars having a height of about 1-5 µm and base diameters of about 100-250 nm ([0030]; [0100]; [0106]-[0108]). The etching process for making the particles comprises depositing a porous layer of dendritic silver on the particles followed by acid etching with HF/AgNO3 to form pillars and then removal of the silver layer ([0030]-[0034]; [0090]-[0097]; Examples). Green teaches that the etching process can be carried out in a reaction chamber having an inlet through which etching solutions can be introduced and an outlet through which the spent solutions can be removed ([0073]; [0077]). Thus, green teaches the surface etched powder particles within a chamber having and inlet and an outlet fluidically coupled thereto.
Regarding the recitation in claim 129 of a “filter configured to lyse a cell” wherein “when passing a composition comprising the cell through the filter from the inlet to the outlet, the plurality of surface etched powder particles contacts the cell, thereby lysing the cell by physical interaction of the cell with the structure” on the particle surface, Hu evidences that nanopillars formed on silicon surfaces using a substantially identical method to that of Green (metal-assisted chemical etching, comprising deposition of a porous dendritic silver layer on the surface of the silicon, followed by etching with HF/AgNO3 to form the pillars and then removal of the silver layer) have bactericidal properties wherein interaction of bacteria with the pillars causes rupture of bacterial cell membranes (Hu, p. 1, 3rd ¶ to p. 4, 1st ¶; Figs. 1-5). The pillars tested by Hu have the same size/spacing as those taught by Green, including a base diameter of about 100 nm and pillar heights of about 0.3-2.4 µm and a pitch (distance between center points of the pillar bases) of about 200-800 nm (Hu, p. 2, 1st-4th ¶; Figs. 1-3). In comparison , Green teaches pillars having a height of about 1-5 µm, base diameters of about 100-250 nm and a fractional pillar surface density of 5-80%, more typically 20% to 50% ([0106]-[0110]) (fractional density is related to pitch by the equation f=πd2/4p2 where d is pillar diameter and p is pitch, such that a pillar of Green having, e.g., a base diameter of about 100 nm and a 20% fractional density would correspond to a pitch of about 200 nm, which is shown to be bactericidal by Hu (Hu, Figs. 2-3)). Thus, Green teaches particles having ranges of pillar geometries and spacings that substantially overlap and/or encompass the geometries/spacings shown by Hu to be bactericidal, and as such the claimed particles are prima facie obvious over Green (see also, MPEP 2144.05). Regarding the recitation of a “filter”, the apparatus of Green meets all of the recited structural and functional limitations and can thus be considered a “filter” within the meaning of the claims.
Regarding claims 130 and 143, Green teaches that the pillars have dimensions in the nanometer range (e.g., base diameters of about 100-250 nm and pores and/or surface roughness on the pillars), and such pillars can thus be considered submillistructures.
Regarding claim 131, Green teaches that the particles can be crystalline or polycrystalline ([0103]).
Regarding claim 134, Hu evidences that the pillars on the surface of the etched particles exhibits bactericidal properties (e.g., Figs. 3-5 and related text).
Regarding claims 135-136, at least some portion of the particles in the etching chamber of Green would sediment on the vessel surface, and such particles can be considered “configured in a surface of an article”. The claims do not require any particular type of interaction with the surface (e.g., embedding, binding, etc.) nor that the surface-associated particles have the capability of lysing the cells. Regarding claim 136, to carry out the etching using any standard glass, plastic or ceramic laboratory vessel.
Regarding claim 137, Hu evidences that silicon nanopillars as taught by Green can lyse cells within a population of cells (e.g., Figs. 3-5 and related text).
Regarding claims 138-139, Hu evidences lysis of >50% of cells (Fig. 5 and related text).
Regarding claim 144, the particles within the etching chamber of Green are not embedded within or adhered to any material (see above; also, the particles would necessarily need access to etching agents).
Regarding claim 145 and 147, it would have been obvious in view of Green to remove the etching agent(s) via the outlet and allow the particles to dry within the chamber (e.g., to facilitate handling and/or packaging for use in downstream applications).
Regarding claim 146, Green teaches use of particles having a significant size range, e.g. 3-100 µm ([0100]). Moreover, a population of ground particles as taught by Green would necessarily have at least some degree of size heterogeneity (even if sieved or the like).
Conclusion
No claim is allowed.
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/ROBERT J YAMASAKI/Primary Examiner, Art Unit 1657