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 .
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.
Claim Rejections - 35 USC § 112(a) – New Matter
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 6 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 6 recites first pelleting the metallic PVP-BiNPs, followed by washing and pelleting a second time. The concept of pelleting the PVP-BiNPs multiple times does not appear to have been disclosed by the original application as filed. As such, the subject matter of claim 6 appears to be new matter.
Claims 12-13 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 12 has been amended to recite an average diameter of 8 to 9 nm. This does not appear to be adequately supported by the original application as filed, which does not appear to disclose this diameter. Claim 12 has also been amended to recite Bi° free of bismuth oxide. The examiner notes that the term Bi° does not appear to have been disclosed in the original application, though the examiner understands this to refer to metallic bismuth (or bismuth in the oxidation state of zero), which is disclosed at least of page 9, paragraph 041 of the instant specification. With that being said, the exclusion of bismuth oxide appears to be new matter not disclosed by the original application.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 10-11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, 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.
Claims 10-11 are drawn to storing the metallic PVP bismuth nanoparticles of claim 9. However, claim 9 is not drawn to metallic PVP bismuth nanoparticles. In contrast, claim 9 is drawn to a method for synthesizing bismuth nanoparticles. As such, it is unclear as to what is being stored in the method of claims 10-11.
For the purposes of examination under prior art, the examiner will proceed with the understanding that claims 10-11 are drawn to storing the particles of claim 12.
Claims 12-13 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, 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 12 is drawn to an antimicrobial PVP coated metallic bismuth nanoparticle. However, claim 12 also recites an average diameter. As best understood by the examiner, the concept of an average diameter applies to a population of particles, but not to a single particle. As claim 12 appears to be drawn to a particle, it is unclear how the subject matter of claim 12 further limits the scope of claim 1.
For the purposes of examination under prior art, the examiner will proceed with the understanding that claim 12 is drawn to a population of particles, and that population has an average size of 8-9 nm. Particles sized outside the recited 8-9 nm are understood to be permitted provided that the average particle size of the population remains at 8-9 nm. Additionally, the examiner understands the size of 8-9 nm to include both the bismuth itself as well as the PVP coating.
Response to Arguments Regarding Indefiniteness Issues
Applicant’s arguments in applicant’s response on 8 December 2025 do not appear to address the indefiniteness issues set forth in the currently applied rejection. As such, applicant’s arguments related to the previously applied indefiniteness rejection have not been addressed substantively by the examiner.
Claim Interpretation – Product-by-Process
The examiner notes the following regarding claims 12-13.
Claim 12 is a product-by-process claim. Such claims are not limited to the manipulations of the recited steps, only to the structure implied by the steps. See MPEP 2113(I). The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process. See MPEP 2113(I). Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing a nonobvious difference between the claimed product and the prior art product. See MPEP 2113(II).
As best understood by the examiner, while a step of adding the chelator and reducing agent is required by claim 1, the skilled artisan would not have been expected these to have been in the final product of claim 12. This is because (a) the reducing agent would have been consumed in the method of reducing bismuth in the +3 oxidation state to bismuth metal and would therefore not have been present; and (b) the chelator would have successfully chelated bismuth ions in the +3 oxidation state but would not have been expected to have successfully chelated bismuth metal. As such, the examiner has proceeded with the understanding that the chelator and reducing agent need not be present in the product of claim 12. Similarly, the alkaline solution in which the bismuth nitrate is present in claim 1 need not be present in the final product, especially because the isolation procedure by centrifugation and washing of claims 6-8 would have removed the alkali.
Claim 13 is drawn to a method of using the product made by the method of claim 1. As such, the limitations in claim 1 further limiting the method by which the product used in the method of claim 13 do not further limit the method of ameliorating bacterial growth. As such, these limitations limiting the method by which the product used in the method of claim 13 has been made will be understood to be product-by-process limitations and will be interpreted in accordance with the two paragraphs above.
Claim 10-11 are drawn to a method of storing the product made by the method of claim 12, as per the examiner’s interpretation of indefinite claims 10-11. As such, the limitations in claim 12 further limiting the method by which the product stored in the method of claims 10-11 do not further limit storage method of claims 10-11. As such, these limitations limiting the method by which the product used in the method of claims 10-11 has been made will be understood to be product-by-process limitations and will be interpreted in accordance with the two paragraphs above.
Response to Arguments Regarding Claim Interpretation Issues
Applicant does not appear to have presented arguments specifically related to the section of the office action mailed on 8 September 2025 entitled “Claim Interpretation – Product-by-Process”, which is reiterated above. Nevertheless, looking at applicant’s arguments, there does appear to be an issue of disagreement. On page 7 of the prior office action mailed on 8 September 2025, the examiner took the position that although the method of claim 1 recites the step of adding the chelator, the skilled artisan would not have expected the chelator to have been present in the final product. Applicant appears to disagree with this, as of applicant’s response on 8 December 2025, page 5, relevant text reproduced below.
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The examiner’s best understanding of this argument is that applicant is arguing that the product of claim 12 comprises a chelator, which is not found the prior art. To the extent that this is applicant’s argument, it is not persuasive because the skilled artisan would not have expected the chelator to have been present in the product recited by claim 12. The examiner presents the following rationale in support of this position.
The examiner notes the following: first, claim 12 recites a product made by the method of claim 1, and the method of claim 1 recites the step of adding a chelator. Nevertheless, this would not necessarily result in a chelator being present in the final product of claim 12. As best understood by the examiner, a chelator can chelate with metal ions, but not necessarily with metals with an oxidation state of zero. This is because chelators interact with metals via dative covalent bonds, in which electron rich chelators form bonds with electron poor metal ions. However, metals with a zero oxidation state are not electron-poor in the same manner that metal ions are electron poor. As such, the skilled artisan would not have expected the chelator added in claim 1 to have bound to bismuth in its metallic oxidation state. In contrast, the skilled artisan would have expected the chelator to have bound to bismuth in its trivalent (i.e. +3) oxidation state, but not to have remained bound to bismuth after its reduction to the zero oxidation state.
Withdrawn Anticipation Rejections
Vazquez-Munoz Reference: Previously in the prosecution history, the examiner rejected the instant claims as being anticipated by Vazquez-Munoz et al. (MethodsX, 2020, 100894, pages 1-7). This rejection has been withdrawn in view of the declaration under 37 C.F.R. 1.130(A) added to the file record on 8 December 2025.
Lei Reference: Previously in the prosecution history, the examiner rejected claim 12 as being anticipated by Lei et al. (Advanced Functional Materials, Vol. 27, 2017, 1702018, pages 1-10, supplemental cover page, and supplemental pages 1-21). This rejection has been withdrawn in view of the amendment to claim 12 reciting particles with an average diameter of 8 to 9 nm. In contrast, the average diameter of the particles of Lei appears to be between about 2.5 nm and 3.0 nm, as of Lei, page 3, figure 1(b), reproduced below.
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As such, the particle size of the composition of Lei differs from the claimed particle size, and overcomes the previously applied anticipation rejection over Lei. This decision does not relate to obviousness rejections which include Lei in the statement of rejection.
Additionally, Lei is not understood to anticipate claim 1. The examiner notes the following differences between the method of Lei and that of claim 1.
First, Lei teaches dissolving Bi(NO3)3 in a mixture of glycerol and ethanol. This does not read on the required alkaline solution. The term alkaline is understood to refer to high pH solution, or a solution with a concentration of hydroxide ion greater than that in neutral pH water. This would not have occurred in the glycerol/ethanol solution of Lei.
Secondly, while Lei teaches Bi(NO3)3 as well as PVP and a reducing agent, it is unclear as to whether Lei teaches a chelator that is separate from these ingredients. Even if, purely en arguendo, the glycerol of Lei was to read on the required chelator, it is still the case that Lei fails to teach the required alkaline solution. As such, the examiner’s understanding of Lei’s use of a solvent system that does not contain water in order to solubilize the Bi(NO3)3 starting material would appear to preclude the presence of both an alkaline solution and a chelator, both of which are required by the instant claims.
Third, the instant claims require adding the reducing agent dropwise at a temperature of 60 to 75°C. In contrast, Lei teaches adding the reducing agent (sodium borohydride) quickly. Lei is also silent regarding the temperature at which this step occurs, which the examiner understands to indicate that this method step occurs at room temperature.
Luo Reference: The instant claims were previously rejected as being anticipated by Luo et al. (Journal of Materials Science: Materials in Medicine, Vol. 23, 2012, pages 2563-2573). This rejection has been withdrawn because the particles of Luo appear to be larger than the claimed particles. In support of this position, the examiner cites Luo, page 2566, right column and page 2567, left column, relevant text reproduced below with highlighting by the examiner.
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The bismuth containing particles described above appear to be sized larger than the 8-9 nm size range required by the instant claims. The examiner notes that the above-reproduced paragraph does describe particles sized 10 nm; however, these particles appear to be Fe3O4 nanoparticles and CdSe/ZnS quantum dots, not bismuth containing nanoparticles.
Luo also is not understood to anticipate claim 1. The examiner notes the following differences between the method of Lei and that of claim 1.
First, Luo teaches dissolving Bi(NO3)3 in N,N-dimethylformamide (DMF). The DMF solution of Luo does not read on the required alkaline solution. The term alkaline is understood to refer to high pH solution, or a solution with a concentration of hydroxide ion greater than that in neutral pH water. This would not have occurred in the DMF solution of Luo.
Secondly, while Luo teaches Bi(NO3)3 as well as PVP and a reducing agent (NaBH4), it does not appear as if Luo teaches a chelator.
Third, the instant claims require adding the reducing agent dropwise at a temperature of 60 to 75°C. Luo does not appear to teach this.
The examiner notes that the reasons for withdrawing rejections applies only to anticipation rejections, and not to obviousness rejections.
Claim Rejections - 35 USC § 103 – Obviousness
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 12-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lei et al. (Advanced Functional Materials, Vol. 27, 2017, 1702018, pages 1-10, supplemental cover page, and supplemental pages 1-21) in view of Gomez et al. (WO 2020/007822 A1).
Claim(s) 12-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Luo et al. (Journal of Materials Science: Materials in Medicine, Vol. 23, 2012, pages 2563-2573) in view of Gomez et al. (WO 2020/007822 A1).
Lei et al. (hereafter referred to as Lei) is drawn to bismuth nanodots protected by polyvinylpyrrolidone, as of Lei, page 1, title and abstract. Lei teaches that the nanodots were prepared by the following process, as of Lei, supplemental page 2, relevant text reproduced below.
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As such, the skilled artisan would have understood that the resultant product would have been that of bismuth nanoparticles coated with PVP.
Luo et al. (hereafter referred to as Luo) is drawn to surface modified bismuth nanoparticles, as of Luo, page 2563, title and abstract. Luo teaches the following, as of page 2565, left column, relevant paragraph reproduced below.
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The skilled artisan would have understood that the product formed by this method would have been a polyvinylpyrrolidone (PVP) coated bismuth nanoparticle.
Neither Lei nor Luo teach using bismuth nanoparticles in an antibacterial method, as required by claim 13. Also, Lei and Luo do not anticipate the required particle size.
Gomez et al. (hereafter referred to as Gomez) is drawn to bismuth metal nanoparticles, as of Gomez, title and abstract. Gomez teaches that bismuth metal particles can be used as an antibacterial, as of Gomez, page 15, lines 9-11, relevant text reproduced below.
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Gomez is not understood to be anticipatory because, although Gomez teaches polyvinylpyrrolidone as a capping agent of the bismuth, it is taught either in a list of (e.g. as of Gomez, page 53 line 24) or in prior art reviewed by Gomez.
It would have been prima facie obvious for one of ordinary skill in the art to have used the nanoparticles of Lei or Luo to have ameliorated bacterial growth. Lei and/or Luo are drawn to bismuth nanoparticles capped by polyvinylpyrrolidone. Lei and/or Luo teaches using these as imaging agents or anticancer agents; nevertheless, Gomez also teaches that bismuth nanoparticles may be used to kill bacteria. As such, the skilled artisan would have been motivated to have used the bismuth nanoparticles of Lei and/or Luo to have predictably killed bacteria, thereby predictably ameliorating bacterial growth with a reasonable expectation of success.
As to claim 12, the claim requires an antimicrobial bismuth nanoparticle. The examiner takes the position that the skilled artisan would have expected the compositions of Lei and Luo to have been antimicrobial even if not taught for this purpose by Lei and Luo. This is because the bismuth in Lei and Luo appears to be the same bismuth required by the instantly claimed subject matter. Something which is old (e.g. the compositions of Lei and Luo) does not become patentable upon the discovery of a new property, and this property need not have been recognized at the time of filing. See MPEP 2112(I & II). Additionally, where the structure in the reference is substantially identical to that of the claims, the claimed properties or functions are presumed to be inherent. See MPEP 2112.01(I). In this case, although there are differences in size between the particles of Lei and Luo and the claimed particle, it is nevertheless the case that the bismuth metal in Lei and Luo appears to be chemically the same as that in the claimed invention. As such, the skilled artisan would have expected the antibacterial properties of Lei and Luo to have been inherent in the claimed composition. Additionally, Gomez teaches antibacterial properties.
As to claim 12, the claim requires a particular particle size. The particle sizes taught by the prior art are not the same as the claimed particle size. Nevertheless, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. See MPEP 2144.05(II)(A). In this case, the general conditions of bismuth metal nanoparticles coated with PVP have been taught by the prior art. As such, it would not have been inventive for the skilled artisan to have discovered the optimum or workable ranges of particle size via routine experimentation. Additionally, it is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, … is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions. See MPEP 2144.05(II)(A), end of paragraph. As best understood by the examiner, a change in the particle size between the prior art and claimed invention would appear to be a change of form, proportions, or degree that would not have been sufficient to sustain a patent.
As to claim 12, the examiner notes that the process described by Lei and Luo differs from the process by which the claimed particles have been formed. Nevertheless, claim 12 is a product-by-process claim, and such claims are not limited to the manipulations of the recited steps, only to the structure implied by the steps. See MPEP 2113(I). Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing a nonobvious difference between the claimed product and the prior art product. See MPEP 2113(II). In this case, both the product of Lei/Luo and the claimed product are of bismuth nanoparticles coated by PVP, though the claimed product has been produced by a different process than that of Lei/Luo. Nevertheless, this is sufficient to shift the burden to applicant to come forward with evidence establishing a nonobvious difference between the claimed product and the prior art product in accordance with MPEP 2113(II). See the section above entitled “Claim Interpretation – Product-by-Process Issues” for more information regarding this issue.
Claim(s) 1-3, 6, 8-9 and 12-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gomez et al. (WO 2020/007822 A1) in view of Ma et al. (Colloids and Surfaces A: Physiochem. Eng. Aspects, Vol. 395, 2012, pages 276-283).
Gomez et al. (hereafter referred to as Gomez) provides various teachings regarding the synthesis of bismuth nanoparticles, as of Gomez, title and abstract.
As to claim 1, the claim requires alkaline Bi(NO3)3 as a starting material. While most of the methods taught by Gomez utilize organic solvent, Gomez teaches an aqueous solution; see e.g. Gomez, page 5, lines 18-22, reproduced below.
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As to claim 1, the claim requires a chelator. Gomez teaches tartaric acid and EDTA as of the above-reproduced paragraph; these are understood to be chelators. Gomez also teaches dimercaptopropanol on page 9, lines 13-15.
As to claim 1, the claim requires polyvinylpyrrolidone. Gomez teaches this as of page 5, lines 7-10.
As to claim 1, the claim requires a reducing agent. Gomez teaches this at least as of page 5, lines 8-10, wherein sodium borohydride as a reducing agent is taught.
Gomez is understood to differ from the claimed invention because, although Gomez teaches an aqueous solution in which Bi(NO3)3 is dissolved, it is unclear that this aqueous solution is alkaline.
Ma et al. (hereafter referred to as Ma) is drawn to a method of synthesis of bismuth nanoparticles, as of Ma, page 276, title and abstract. The method of Ma entails the following, as of Ma, page 277, left column, section 2.2, relevant text reproduced below.
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As best understood by the examiner, the above-reproduced paragraph describes a synthesis in aqueous environment, with NaOH rendering the environment basic. Ma teaches H2C4H4O6, which is tartaric acid and is understood to be a chelator. Ma teaches sodium hypophosphite (NaH2PO2 with one water of hydration), which is understood to be a reducing agent.
Ma fails to teach polyvinylpyrrolidone.
It would have been prima facie obvious for one of ordinary skill in the art to have combined the polyvinylpyrrolidone of Gomez with the aqueous bismuth nanoparticle method of Ma. Ma teaches a method of synthesis of bismuth nanoparticles; however, this method does not include polyvinylpyrrolidone. Gomez teaches that polyvinylpyrrolidone is useful as a stabilizing agent, as of Gomez, page 5, end of top paragraph. As such, the skilled artisan would have been motivated to have included polyvinylpyrrolidone in the method of Ma in order to have predictably stabilized the bismuth nanoparticles with a reasonable expectation of success.
As to claim 1, the claim requires alkaline Bi(NO3)3 as a starting material. This is taught by Ma.
As to claim 1, the claim requires a chelator. The tartaric acid of Ma as well as the dimercaptopropanol of Gomez, page 9, lines 13-15, are understood to read on this requirement.
As to claim 1, the claim requires polyvinylpyrrolidone. Gomez teaches this as of page 5, lines 7-10.
As to claim 1, the claim requires a reducing agent. Ma teaches sodium hypophosphite as a reducing agent. Gomez teaches sodium borohydride as a reducing agent as of at least page 5 lines 5-10.
As to claim 1, the claim requires heating to 60 to 75°C. Ma teaches heating to 90°C, as of the above-reproduced text from Ma, page 277, left column, section 2.2. Nevertheless, generally, differences in temperature between the prior art and claimed invention will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such temperature is critical. See MPEP 2144.05(II)(A). In this case, no evidence of criticality has been provided. Additionally, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. See MPEP 2144.05(II)(A). In this case, the general conditions of heating bismuth nitrate in aqueous base along with a chelator and a reducing agent have been taught by the prior art. As such, it would not have been inventive for the skilled artisan to have determined the optimum or workable temperature range by routine experimentation.
As to claim 1, the claim requires that the reducing agent be added dropwise. This does not appear to have been taught by the prior art. Nevertheless, the skilled artisan would have been motivated to have added a component dropwise that would have been likely to have engaged in an exothermic reaction. The skilled artisan would have understood that hydrides such as sodium borohydride, which has been taught by Gomez, are unstable in water because the hydride would react with hydrogen ions in water to form H2 hydrogen gas. As such, the skilled artisan would have been motivated to have added a hydride reducing agent dropwise to have prevented excessive heat release in an excessively exothermic reaction.
As to claim 2, Gomez teaches dimercaptopropanol, as of page 9, lines 13-15.
As to claim 3, Gomez teaches sodium borohydride, as of page 5, lines 8-10.
As to claim 6, Gomez teaches the following, as of page 62, relevant text reproduced below.
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Gomez teaches a wash as of the above-reproduced text.
As to claim 8, Gomez teaches 4000 rpm centrifugation, as of the above-reproduced text. It is unclear if this would have read on the claimed requirements because the claims recite centrifugal force in “g”, whereas Gomez teaches centrifugal speed in rpm (i.e. revolutions per minute). Nevertheless, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. See MPEP 2144.05(II)(A). In this case, the general conditions of centrifugation are taught by Gomez. As such, it would not have been inventive for the skilled artisan to have discovered the optimum or workable centrifugal speed or g-force via routine experimentation.
As to claim 9, the rationale provided by the examiner regarding claim 6 is also understood to be applicable to claim 9.
As to claim 12, the skilled artisan would have understood the composition formed by the method of Gomez, when using polyvinylpyrrolidone, to have had all of the features required by claim 12.
As to claim 12, the claim requires a particular particle size. Gomez teaches the following, as of page 49, relevant text reproduced below.
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This overlaps with the claimed size range of 8-9 nm. While the prior art does not disclose the exact claimed values, but does overlap: in such instances even a slight overlap in range establishes a prima facie case of obviousness. See MPEP 2144.05(I).
As to claim 13, Gomez teaches that bismuth metal particles can be used as an antibacterial, as of Gomez, page 15, lines 9-11, relevant text reproduced below.
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As such, the skilled artisan would have been motivated to have used the particles of Gomez in a method of ameliorating bacterial growth.
Claim(s) 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gomez et al. (WO 2020/007822 A1) in view of Ma et al. (Colloids and Surfaces A: Physiochem. Eng. Aspects, Vol. 395, 2012, pages 276-283), the combination further in view of Wang et al. (Journal of Physical Chemistry B, Vol. 109, 2005, pages 7067-7072) and Beresini et al. (US 2019/0177366 A1).
Gomez is drawn to methods of making bismuth metal nanoparticles. Ma is drawn to a method of making bismuth metal nanoparticles utilizing polyvinylpyrrolidone.
Neither Gomez nor Ma teach the molecular weight of the polyvinylpyrrolidone.
Wang et al. (hereafter referred to as Wang) is drawn to a method of making bismuth nanoparticles protected by polyvinylpyrrolidone (PVP), as of Wang, page 7067, title and abstract. The method of Wang utilizes PVP with a molecular weight of 55,000 Daltons, as of Wang, page 7067, right column, section 2.1.
Beresini et al. (hereafter referred to as Beresini) is drawn to PCSK9 inhibitors, as of Beresini, title and abstract. Beresini teaches 10 kDa (i.e. 10,000 Dalton) polyvinylpyrrolidone as a stabilizer, as of paragraph 0369.
Wang fails to teach the required alkaline solution of bismuth nitrate, and Beresini is not drawn to bismuth nanoparticles.
It would have been prima facie obvious for one of ordinary skill in the art to have optimized the polyvinyl pyrrolidone of Gomez to have had the molecular weight required by the instant claims. Gomez is drawn to the use of polyvinyl pyrrolidone as a stabilizer for bismuth nanoparticles, but is silent as to the molecular weight of the polyvinyl pyrrolidone. Wang teaches polyvinylpyrrolidone with a molecular weight of about 58,000 Daltons for making and stabilizing Bismuth nanoparticles. While this molecular weight exceeds the claimed molecular weight, Beresini teaches the use of 10 kDa (i.e. 10,000 Dalton) polyvinylpyrrolidone as a stabilizer. As such, the skilled artisan would have been motivated to have optimized the molecular weight of the polyvinylpyrrolidone to have been 10,000 Daltons to have predictably stabilized the bismuth nanoparticles of Gomez with a reasonable expectation of success.
Additionally, the examiner notes that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. See MPEP 2144.05(II)(A). In this case, the general conditions of bismuth nanoparticles stabilized by polyvinyl pyrrolidone have been taught by the prior art. As such, it would not have been inventive for the skilled artisan to have discovered the optimum or workable ranges of the molecular weight of the polyvinyl pyrrolidone via routine experimentation.
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gomez et al. (WO 2020/007822 A1) in view of Ma et al. (Colloids and Surfaces A: Physiochem. Eng. Aspects, Vol. 395, 2012, pages 276-283), the combination further in view of Brown et al. (Chemistry of Materials, Vol. 16, 2014, pages 2266-2274).
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gomez et al. (WO 2020/007822 A1) in view of Ma et al. (Colloids and Surfaces A: Physiochem. Eng. Aspects, Vol. 395, 2012, pages 276-283), the combination further in view of Jiang et al. (Applied Catalysis B: Environmental, Vol. 205, 2017, pages 523-540).
Gomez is drawn to methods of making bismuth metal nanoparticles. Ma is drawn to a method of making bismuth metal nanoparticles utilizing polyvinylpyrrolidone.
Neither Gomez nor Ma teach the required storage conditions.
Brown et al. (hereafter referred to as Brown) is drawn to bismuth nanoparticles, as of Brown, title and abstract. Brown teaches storage at 4 °C, as of Brown, page 2268, left column, top paragraph.
Jiang et al. (hereafter referred to as Jiang) teaches bismuth nanoparticles, as of Jiang, title and abstract. Jiang teaches storage of said nanoparticles in a manner that they are protected from light, as of Jiang, page 533, right column, top paragraph.
Neither Brown nor Jiang teach PVP.
It would have been prima facie obvious for one of ordinary skill in the art to have stored the nanoparticles of Gomez in view of Ma at 4°C, as of Brown, or free from light, as of Jiang. The combination of Gomez in view of Ma is drawn to bismuth nanoparticles. Brown and Jiang are also drawn to bismuth nanoparticles, and teach storing said nanoparticles either at 4°C or free from light. As such, the skilled artisan would have been motivated to have stored the nanoparticles of Gomez in view of Ma either at 4°C or free from light in order to have predictably stored said particles in a manner that they remain stable for a long period of time with a reasonable expectation of success.
Response to Arguments Regarding Obviousness Rejections
Applicant has provided arguments regarding the previously applied rejections, as of applicant’s response on 8 December 2025. These arguments are addressed below.
As an initial matter, the examiner notes that arguments have been presented regarding the previously-applied anticipation rejections over Lei et al. (Advanced Functional Materials, Vol. 27, 2017, 1702018, pages 1-10, supplemental cover page, and supplemental pages 1-21) and Luo et al. (Journal of Materials Science: Materials in Medicine, Vol. 23, 2012, pages 2563-2573). The previously applied anticipation rejections over these references have been withdrawn. With that being said the arguments presented in part B of applicant’s response on page 6 through the top of page 8 would appear to be moot. With that being said some of the arguments presented in this section of applicant’s response would still appear to be relevant and are substantively addressed below.
Applicant makes the following argument as of page 5, last three lines, reproduced below.
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The examiner’s best understanding of this argument is that applicant is arguing that the product of claim 12 comprises a chelator, which is not found in prior art references Lei and/or Luo. To the extent that this is applicant’s argument, it is not persuasive.
The examiner notes the following: first, claim 12 recites a product made by the method of claim 1, and the method of claim 1 recites the step of adding a chelator. Nevertheless, this would not necessarily result in a chelator being present in the final product of claim 12. As best understood by the examiner, a chelator can chelate with metal ions, but not necessarily with metals with an oxidation state of zero. This is because chelators interact with metals via dative covalent bonds, in which electron rich chelators form bonds with electron poor metal ions. However, metals with a zero oxidation state are not electron-poor in the same manner that metal ions are electron poor. As such, the skilled artisan would not have expected the chelator added in claim 1 to have bound to bismuth in its metallic oxidation state. In contrast, the skilled artisan would have expected the chelator to have bound to bismuth in its trivalent (i.e. +3) oxidation state, but not to have remained bound to bismuth after its reduction to the zero oxidation state.
As such, while compositions of Lei and Luo lack a chelator, that difference is insufficient to distinguish Lei and Luo from the invention of claim 12 because the skilled artisan would not have expected the chelator to have been present in the composition of claim 12.
Applicant then argues that the particles of Lei and Luo are designed for CT imaging or photothermal cancer therapy, and the skilled artisan would not have expected these particles to have had antibacterial properties. This is not persuasive. Something which is old (e.g. the compositions of Lei and Luo) does not become patentable upon the discovery of a new property, and this property need not have been recognized at the time of filing. See MPEP 2112(I & II).
Additionally, where the structure in the reference is substantially identical to that of the claims, the claimed properties or functions are presumed to be inherent. See MPEP 2112.01(I). In this case, although there are differences in size between the particles of Lei and Luo and the claimed particle, it is nevertheless the case that the bismuth metal in Lei and Luo appears to be chemically the same as that in the claimed invention. As such, the skilled artisan would have expected the antibacterial properties of Lei and Luo to have been inherent in the claimed composition.
The examiner notes that apparatus claims cover what a device is, not what a device does; see MPEP 2114(II) where the examiner understands this rationale to apply to composition claims in the same manner that it applies to apparatus claims. As such, the claims (other than claim 13) cover what the composition is (e.g. bismuth nanoparticles), not what the composition does (e.g. act as an antimicrobial).
Also in this vein, the examiner notes that the reason or motivation to modify the reference may often suggest what the inventor has done, but for a different purpose or to solve a different problem. It is not necessary that the prior art suggest the combination to achieve the same advantage or result discovered by applicant. See MPEP 2144(IV). In this case, the fact that the prior art suggested forming bismuth nanoparticles for a different purpose than what is recited by the instant claims is not sufficient to overcome the cited prior art.
Applicant then makes the following argument regarding the issue of reaction temperature, as of page 8, second full paragraph in part B, relevant text reproduced below.
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This is not persuasive. While applicant has asserted that there are unexpected results associated with the recited temperature range, applicant has not pointed to where in the specification and drawings these are allegedly disclosed. The examiner reviewed the instant specification and drawings, and was unable to find evidence of unexpected results related to the recited temperature range. The burden is on applicant to establish that results are unexpected and significant, and applicant does not appear to have met that burden. See MPEP 716.02(b)(I & II).
Applicant then argues that lower or higher temperatures cause undesired products, as of applicant’s response, page 8, last paragraph in section B. Specifically, applicant argues that overheating causes immediate oxidation and large particles, whereas lower temperatures result in a highly unstable suspension that precipitates within minutes after synthesis. This is not persuasive. To be of probative value, any objective evidence should be supported by actual proof, and attorney argument cannot take the place of evidence. See MPEP 716.01(c)(I & II) as well as MPEP 2145(I). Applicant’s arguments that undesirable effects occur if the temperature is outside the claimed range appears to be attorney argument rather than evidence. This attorney argument is insufficient to provide evidence that conducting a method with a comparative temperature outside the claimed range would have resulted in the formation of an inferior product.
Applicant does not appear to have presented additional arguments regarding claims 4-5 and the secondary references used to reject these claims in part C of applicant’s response on page 8. As such, the previously applied rejection of claims 4-5 has been maintained by the examiner.
Conclusion
No claim is 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 ISAAC SHOMER whose telephone number is (571)270-7671. The examiner can normally be reached 7:30 AM to 5:00 PM Monday Through Friday.
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ISAAC . SHOMER
Primary Examiner
Art Unit 1612
/ISAAC SHOMER/ Primary Examiner, Art Unit 1612
Prosecution Insights