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 .
Applicant’s submission filed on June 4, 2026 has been entered and considered. Rejections and/or objections not reiterated from the previous action mailed February 5, 2026 are hereby withdrawn. The following rejections and/or objections are either newly applied or are reiterated and are the only rejections and/or objections presently applied to the instant application. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Election/Restrictions
Applicant’s election without traverse of Group 1, claims 1 and 3-10 in the reply filed on October 20, 2025 has been acknowledged. Based on review of the claims, Group 4, claim 16, drawn to a method of producing a culture medium comprising exosomes from umbilical cord blood stem cells by culturing these cells in media supplemented with GDF-11 was rejoined.
Claims 11-15 and 21-24 were previously withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected inventions, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on October 20, 2025.
Applicant has elected the following species:
Claim 1: Applicant elects growth factors of GDF-11, EGF, FGF2, TGF-β1 and VEGF, i.e., “5GF combination”
Claims 4/5 related to the effect/result: Applicant elects Claim 5
Claim 5 sub-items: Applicant elects a higher ability to regenerate the skin
Claim 7 related to cell culture medium: Applicant elects DMEM
Claim 8 related to product type: Applicant elects cell culture medium containing exosomes released by the umbilical cord blood stem cells
Claim 9 related to formulation: Applicant elects culture medium frozen to powder
Claim 10 related to cell type and effect: Applicant elects fibroblasts and keratinocytes and migration and proliferation.
Based on Applicant’s amended claims dated August 11, 2025 removing “and/or to inhibit inflammation”, all species of claim 5 were previously rejoined. In view of the prior art, the formulation species of claim 9 of gelled or frozen or dried to powder were previously rejoined.
Claim 4 was withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species.
Status of the Claims
Applicant has amended claim 1 to recite serum-free media supplemented with a five-growth factor combination of GDF-11, EGF, FGF2, TGF-β1, and VEGF and that the recited concentration is related to exosome particles per milliliter. Claim 5 has been amended to correct matters of clarity. Claim 7 has been amended to remove trademarks. Claim 16 has been canceled. Withdrawn claims 22 and 24 have been canceled. Claims 4, 11-15, 21, and 23 stand withdrawn.
Claims 1, 3, and 5-10 are examined on the merits.
New Claim Rejections - 35 USC § 112(b)
Claim 8 is 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 8 as amended recites the limitation “further comprising formulating the culture medium containing the released exosomes or the exosomes isolated from the culture medium for a selected use” which renders the scope of the claim indefinite. The limitation “a selected use” is not defined by the claim or by Applicant’s instant specification, and no method steps are recited directed to the use. Therefore, a skilled artisan would not be able to determine what use is intended to be encompassed by the claim. Appropriate correction is required.
New Claim Rejections - 35 USC § 103
This is a new rejection necessitated by Applicant’s amendment. However, this rejection shares substantial similarity to the rejection as previously set forth in the office action dated February 5, 2026. Any aspect of Applicant’s traversal that pertains to the rejection as newly set forth will be provided following the new statement of rejection.
Claims 1, 3, and 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Wolvetang et al. (WO 2009055868, hereafter “Wolvetang”) in view of Kern et al. (2006, Comparative analysis of mesenchymal stem cells from bone marrow, umbilical cord blood, or adipose tissue. Stem Cells, 24(5), 1294-1301, hereafter “Kern”), Kim et al. (US 20190111108, hereafter “US ‘108” for clarity ) and Kim et al. (2017, Exosomes derived from human umbilical cord blood mesenchymal stem cells stimulates rejuvenation of human skin. Biochem. and Biophys. Res. Comm., 493(2), 1102-1108., hereafter “Kim”).
With regard to claim 1, Wolvetang teaches a method of maintaining stem cells in an undifferentiated state and a culture media for maintenance of stem cells in an undifferentiated state (Pg. 1, lines 10-15). Wolvetang teaches that stem cells can be derived from umbilical cord blood (Pg. 2, lines 5-6) and that the culture media for culturing a stem cell in an undifferentiated state comprises GDF (Pg. 5, lines 1-2). Wolvetang teaches an exemplary embodiment where human embryonic stem cells were cultured in serum-free media supplemented with GDF-11 (also known as BMP-11) at 20 ng/ml and FGF2 (also known as bFGF) at 20 ng/ml (Pg. 44, lines 29-31 and Pg. 49, lines 24-29) while maintaining their undifferentiated state (Pg. 49, lines 24-29).
While Wolvetang does teach that stem cells can be derived from umbilical cord blood, all exemplary embodiments are drawn toward use of embryonic stem cells.
Kern teaches that mesenchymal stem cells (MSCs) derived from umbilical cord blood can be cultured longer and show higher proliferative ability compared to MSCs from other sources (Abstract) thus exhibiting the highest expansion potential amongst the MSCs investigated by Kern (Pg. 1300, right col., 2nd full para., lines 10-11). Further, Kern teaches that MSCs from umbilical cord blood can be obtained less invasively than MSCs derived from other sources (Pg. 1294, left col., 2nd para.).
Therefore it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to choose stem cells derived from umbilical cord blood as taught by Kern for use in the method of culturing stem cells such that stem cells are maintained in an undifferentiated state as taught by Wolvetang with a reasonable expectation of success. Since Kern teaches that stem cells from umbilical cord blood can be obtained relatively easily and exhibit increased potential for expansion, a skilled artisan would be motivated to choose umbilical cord blood stem cells in order to generate the largest number of undifferentiated stem cells, which Wolvetang teaches can be used for clinical applications such as generation of disease models, testing of pharmaceuticals and/or therapeutics, and tissue repair and/or regeneration (Pg. 2, lines 25-28). A skilled artisan would have had a reasonable expectation of success as both Wolvetang and Kern teach culture of stem cells and would have every reason to expect that Wolvetang’s culture method would achieve similar results when used to culture umbilical cord blood stem cells.
While the combined teachings of Wolvetang and Kern teach culture of umbilical cord blood stem cells in serum free culture media supplemented with 20 ng/ml of GDF-11 at and 20 ng/ml of FGF2, they are silent as to use of serum-free media supplemented with GDF-11, FGF2, as well as EGF, TGF-β1, and VEGF.
US ‘108 teaches culturing of umbilical cord blood-derived mesenchymal stem cells in media comprising DMEM containing EGF, VEGF, and TGF-β1 (Example 1, Paras. [0085], [0079]) promotes proliferation of stem cells (Para. [0079]) and that that EGF, TGF-β1, and VEGF were supplied to culture media at concentrations of 1 ng/ml or 10 ng/ml (See Example 7-2).
Therefore, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to apply addition of the growth factors EGF, TGF-β1, and VEGF at the instantly claimed concentrations which is used for culture of umbilical cord blood derived mesenchymal stem cells as taught by US ‘108 to the method of culturing umbilical cord blood stem cells in culture media comprising GDF-11 and FGF2 as taught by Wolvetang and Kern with a reasonable expectation of success. Since US ‘108 teaches that addition of EGF, TGF-β1, and VEGF provides the benefit of promoting stem cell proliferation in culture and Wolvetang teaches that culture with GDF-11 and FGF2 is beneficial for maintaining stem cells in an undifferentiated state (i.e., maintaining “stemness”), which is related to cellular proliferation, it would be obvious to a skilled artisan to combine use of growth factors EGF, TGF-β1, and VEGF in culture media with use of growth factors GDF-11 and FGF2 in culture media as all these growth factors are taught in the art to for the purpose of increasing proliferation/maintaining stemness of umbilical cord blood derived mesenchymal stem cells, thereby increasing culture efficiency and generating more stem cells for subsequent therapeutic use.
While the combined teachings of Wolvetang, Kern, and US ‘108 teach culture of umbilical cord blood stem cells in serum free culture media comprising GDF-11, EGF, FGF2, TGF-β1, and VEGF at the instantly claimed concentrations, Wolvetang, Kern, and US ‘108 are silent as to secretion of exosomes from umbilical cord blood stem cells and specific concentrations of released exosomes.
Kim teaches that umbilical cord blood derived mesenchymal stem cells (UBC-MSCs) secrete exosomes that can promote cell migration in fibroblasts (Abstract). Kim teaches that UBC-MSCs were seeded at 1.89 x 105 cells per T25 flask and “conditioned” culture media was collected after 96 hours (Pg. 1103, left col., 3rd full para.) prior to exosome isolation and exosome particle analysis (i.e., diameter and concentration). Kim teaches that exosome concentration from UBC-MSCs seeded at 1.89 x 105 cells per T25 flask and maintained in culture for 96 hours was measured as 1.23 x 1011 particles/ml (Table 2). However, for subsequent investigation of effects of UBC-MSC exosome application on fibroblasts, Kim teaches that an optimal exosome concentration of 1 x 109 particles/ml (Pg. 1105, left col. 3rd para.) was used to examine the therapeutic effects of UCB-MSC exosomes on growth of fibroblasts.
As Kim teaches that media from cultured UCB-MSCs comprise exosomes derived from the UCB-MSCs (Abstract), one having ordinary skill in the art would have every reason to believe that the method of culturing stem cells derived from umbilical cord blood as taught by Wolvetang and Kern would generate culture media comprising exosomes which had been released by umbilical cord blood stem cells. Additionally, the concentration of exosomes released into media during the culture of stem cells would be recognized by one having ordinary skill in the art as dependent on the number of stem cells in culture, the size of the culture vesicle, the amount of media, time in culture, etc., therefore, it would be obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to optimize conditions such as plating density, culture vesicle size, amount of media, and/or time in culture in the method of culturing umbilical cord blood derived stem cells as taught by the combination of Wolvetang, Kern, and US ‘108 to arrive at the optimal concentration of UCB-MCS exosomes for promoting cell growth of 1 x 109 particles/ml as taught by Kim with a reasonable expectation of success. A skilled artisan would have readily recognized that the concentration of exosomes is a results-effective variable which could be optimized (See MPEP 2144.05(II)). Thus, a skilled artisan would be motivated to alter the plating density as taught by Kim in order to generate a culture media comprising UCB-MSC exosomes at the optimal concentration for therapeutic effects in order to eliminate the method step of diluting the conditioned media comprising UCB-MSC exosomes to reach the optimal concentration.
With regard to claims 3 and 7, as detailed above and incorporated herein, the combined teachings of Wolvetang, Kern, US ‘108, and Kim teach culture of umbilical cord blood stem cells in serum free media supplemented with GDF-11, FGF2, EGF, TGF-β1, and VEGF to produce “conditioned” culture medium comprising exosomes at a concentration of 1 x 109 particles/ml. While exemplary embodiments of Wolvetang teach use of KOSR medium (Examples 1 and 4, Tables 2 and 4), Wolvetang also teaches that serum-free Knockout DMEM can be used for generation of embryonic cell cultures (Pg. 20, 2nd para.).
Wolvetang is silent as to the use of serum-free DMEM.
Kim teaches culture of umbilical cord blood mesenchymal stem cells (UBC-MBCs) in media comprising DMEM and FGF2 (Pg. 1103, left col., 3rd full para.), which is considered to reasonably read on serum-free media; and subsequent isolation, characterization (Pg. 1104, Characterization of USC-CM exosomes), and investigation of potential use of the UBC-MBC derived exosomes for skin regeneration (Figs 3 and 4 and Pg. 1108, left col.).
Therefore, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention to choose DMEM media as taught by Kim in the method of culturing umbilical cord blood stem cells in serum-free media comprising GDF-11, FGF2, EGF, TGF-β1, and VEGF as taught by the combination of Wolvetang, Kern, US ‘108, and Kim with a reasonable expectation of success. One having ordinary skill in the art would have been motivated to choose DMEM as taught by Kim since Kim directly teaches culture of umbilical cord blood mesenchymal stem cells, characterization of exosomes released into the culture media by umbilical cord blood mesenchymal stem cells, and subsequent use of the exosomes for skin rejuvenation (Abstract). Therefore, a skilled artisan would be likely to choose use of DMEM media for culture of UBC-MSCs as taught by Kim in order to replicate the culture conditions which showed successful generation of culture medium comprising exosomes from USC-MBCs and generation of exosomes exhibiting positive effects on skin, as a skilled artisan would recognize these characteristics would be important for therapeutic or commercial use of the exosomes.
With regard to claim 6, as detailed above in claim 1 and incorporated herein, Kim teaches exosome particle analysis isolated from “conditioned media” generated by culture of UCB-MSCs. Kim teaches that exosomes from UCB-MCS had an average particle size of 120nm (Fig. 1, C-iii and Pg. 1104, right col., 1st para.) and exhibited more standardized/consistent small size (Pg. 1108, left col., 1st para., Fig. 1 C-iii) which is considered to reasonably read on having uniform particle size distribution.
Response to Arguments
Applicant's arguments filed June 4, 2026 are acknowledged and have been fully considered but they are not persuasive.
Claims 1, 6-7, and 16, reciting a media composition comprising GDF-11 and at least one other growth factor selected from EGF, FGF2, TGF-β1, and VEGF; were rejected under 35 U.S.C. 103 as being obvious over Wolvetang, Kern, and Kim. Claims 1 and 3, reciting culture in media comprising GDF-11, EGF, FGF2, TGF-β1, and VEGF (“5GF”), were alternately rejected under 35 U.S.C. 103 as being obvious over Wolvetang, Kern, US ‘108, and Kim.
Claim 16 has been canceled rendering Applicant’s traversal moot. Applicant’s traversal of all rejections is drawn to the limitation of culture in media comprising the 5GF combination of growth factors as recited in amended claim 1 and therefore the traversal has been addressed as such.
Applicant traverses that the supplied references provide “isolated teachings” and that none teach the claimed 5GF media for producing a defined exosome containing culture medium from cord-blood derived stem cells (Pg. 14-15, A). Applicant traverses that the rejection utilizes a combination of references (Wolvetang, Kern, Kim, US ‘108, Yeo, Mathen, and Casado-Diaz), “each cited for a different fragment”, which do not identify Applicant’s claimed method of controlling the secretory phenotype of cord blood stem cells in order to produce a high potency exosome containing culture medium and that the Office has relied in improper hindsight reasoning (Pg. 19, F).
Regarding the application of US ‘108, Applicant traverses that US ‘108 teaches that EGF, FGF2, TGF-β1, and VEGF regulates endogenous cellular expression of GDF-11 but does not teach addition of exogenous GDF-11 thereby providing a skilled artisan reason to omit GDF-11.
Applicant further traverses that instantly claimed released exosome concentration is not a result effective variable which could be determined by optimization as none of the prior art identifies the 5GF media as the factor which determines exosome concentration, size uniformity, protein content, and skin regeneration effects. Applicant traverses that the prior art of Kim is a dilution of exosomes to a working concentration utilized for downstream assays whereas the instantly claimed exosome concentration is an output of the culture process and not a “post-hoc dilution” and that nothing in the art teaches that “down-tuning a culture to natively release at ~109 particles/mL is desirable” (Pg. 17-18, D).
Applicants traversal has been fully considered but is not persuasive.
In response to applicant's argument that the examiner has combined an excessive number of references, reliance on a large number of references in a rejection does not, without more, weigh against the obviousness of the claimed invention. See In re Gorman, 933 F.2d 982, 18 USPQ2d 1885 (Fed. Cir. 1991). 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).
As detailed supra, the prior art of Wolvetang is supplied for the disclosure of methods to maintain undifferentiated cultures of stem cells, including those derived from umbilical cord blood, in serum-free media comprising growth factors GDF-11 and FGF2 at the instantly claimed concentrations and reasons why preventing stem cell differentiation is important for future use. Since the exemplary embodiments of Wolvetang are directed toward culture of embryonic stem cells, the prior art of Kern is supplied for support that it would be obvious for a skilled artisan to choose to culture umbilical cord blood stem cells because they are easier to obtain and have higher proliferative ability. The prior art of US ‘108 is supplied for the teaching that culture of umbilical cord blood stem cells in media comprising growth factors EGF, TGF-β1, and VEGF at the instantly claimed concentrations are known to increase proliferation of stem cells maintained in culture, thereby providing the benefit of a larger number of undifferentiated stem cells. Thus, the disclosures of Wolvetang, Kern, and US ‘108 are all drawn towards culturing of stem cells including umbilical cord blood derived stem cells and Wolvetang and US ‘108 disclose the benefit of culturing stem cells in media comprising the instantly claimed growth factors. The prior art of Wolvetang discloses use of populations of undifferentiated stem cells for therapeutic purposes (Pg. 2, lines 25-28) and US ‘108 discloses that the factors secreted during culture of umbilical cord blood stem cells can also be used in therapeutic applications such as skin regeneration and wound healing (Para. [0042]). The prior art of Kim is also drawn to culture of umbilical cord blood stem cells and related skin rejuvenation/wound healing ability (Abstract; Pg. 1102, right col.) and is applied for the teaching that, in culture in media comprising growth factors, umbilical cord blood stem cells release exosomes which have skin rejuvenation and wound healing functions. The prior art of Yeo discloses human mesenchymal stem cells, including those derived from umbilical cord blood, are prolific producers of exosomes in their undifferentiated state. Thus, the prior art of Wolvetang, US ‘108, and Kim are drawn toward therapeutic uses of cord blood derived stem cells and factors secreted by the stem cells and the prior art of Kim and Yeo are drawn to exosome production by cord blood derived stem cells. The prior art of Mathen is supplied for the disclosure of formulation (i.e. lyophilization, gelling) of culture medium comprising exosomes secreted by cord blood derived stem cells for therapeutic applications including skin care and wound healing. Kim discloses that the skin rejuvenation/wound healing functions of exosomes from cord blood derived stem cells improve proliferation and migration of human fibroblasts and the prior art of Casado-Diaz discloses that cord blood derived stem cells are used for skin healing and activate proliferation and migration of fibroblasts and keratinocytes. Thus, the prior art of Kim, Mathen, and Casado-Diaz are drawn toward functional effects of cord blood derived exosomes.
Regarding Applicant’s assertion that US ‘108 teaches away from addition of GDF-11 in the culture media. Culture of stem cells in media comprising the growth factors GDF-11 and FGF2 is disclosed by Wolvetang as a method of maintaining pluripotency and reducing differentiation, which is related to proliferation. US ‘108 discloses that addition of growth factors such as EGF, TGF-β1, and VEGF promotes proliferation of stem cells. Thus, the teachings of the prior art disclose use of the instantly claimed growth factors in culture of umbilical cord blood derived stem cells for the same purpose – cellular proliferation. The prior art of Kim discloses that mesenchymal stem cells are known to secrete growth factors such as EGF and bFGF which have wound healing abilities (Pg. 1102, right col., 1st para.) and that umbilical cord derived stem cells secrete higher amounts of wound healing factor (Pg. 1102, right col., 2nd para.). Therefore, a skilled artisan would recognize that all growth factors produced by umbilical cord derived stem cell would eventually be secreted. As the prior art discloses that the instantly claimed growth factors are useful for the purpose of maintaining stemness and cellular proliferation, adding EGF, TGF-β1, and VEGF as disclosed by US ‘108 to culture media comprising GDF-11 and FGF2 as taught by Wolvetang could easily be envisioned by a skilled artisan in order to ensure that these proliferation-promoting growth factors are present in culture media in sufficient quantities for their functional effects.
Regarding Applicant’s traversal that the prior art of record does not identify the 5GF cocktail which results in the instantly released exosome concentration and phenotype and, therefore, a skilled artisan would not recognize the released exosome concentration as a result-effective variable. As detailed supra, the prior art teaches that culture of cord blood derived stem cells in media comprising the instantly claimed growth factors results in stem cell pluripotency maintenance and increased stem cell proliferation and a skilled artisan would expect that the number of pluripotent stem cells in culture would also affect released exosome concentration. The prior art of Kim discloses that culture of cord blood derived stem cells seeded at 1.89 x 105 cells per T25 flask in media comprising 10 ng/mL of EGF and FGF2 for 4 days results in a released exosome concentration of approximately 1.23 x 1011 exosomes/mL. It is noted that Applicant’s instant claims recite a order of magnitude released exosome concentration of 0.5 x 109 to 5 x 109 exosomes/mL, but Applicant has not disclosed any measurements of released exosome particle concentration at any specific concentrations of growth factors or at any timepoint in culture. Applicant has provided no details regarding the number of cells plated or size of the culture vessel and recites culture media comprising concentrations ranging from 1-20 ng/mL for all growth factors and a time in culture of 1 to 4 days (See Example 1). Therefore, Applicant has not established the criticality of the claimed culture conditions for exosome production. However, since the prior art teaches that cord blood derived stem cells produce exosomes, a skilled artisan would expect that exosome concentration would increase, at minimum, based on increased number of cells in culture and amount of time in culture. Since Kim discloses that 1 x 109 exosomes was optimal for examination of exosome functional effects, a skilled artisan could easily envision reducing the number of cells and/or time in culture in order to arrive at the exosome concentration as taught by Kim. Additionally, Applicant’s claimed functional profile is based on extraction of released exosomes in order to use a specific amount of extracted exosomes to determine functional effects, and not to use of the endogenously released exosome concentration based on culture in 5GF media (See examples 3 and 4). Thus, Applicant’s functional profile is also based on a post hoc process of adjusting the number of released exosomes to a desired amount, 2x108 exosomes, which is a smaller number of exosomes than the lower limit of claimed released concentration of 0.5x109 exosomes/mL.
Regarding expectation of success, Applicant asserts that the purpose disclosed by Wolvetang, maintenance of undifferentiated stem cells by culturing stem cells in media comprising growth factors, is different from Applicant’s claimed invention of altering the exosome output of stem cells by culturing stem cells in media comprising growth factors. Applicant asserts that a skilled artisan would have no reason to expect Wolvetang’s conditions of maintaining pluripotency to yield the claimed exosome release concentration and functional effects and that that motivation asserted by the Office is based on a goal which is different from that of the instant invention. Applicant traverses that the Office has supplied motivation to grow more stem cells, but not to produce an exosome containing culture medium having the instantly claimed exosome concentration and skin-regeneration effects (Pg. 15-16, B).
Applicants traversal has been fully considered but is not persuasive.
MPEP 2144 (IV) states that the reason or motivation to modify a 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, e.g., In re Kahn, 441 F.3d 977, 987, 78 USPQ2d 1329, 1336 (Fed. Cir. 2006). In instant case, the prior art teaches culture of umbilical cord blood derived stem cells in culture medium comprising growth factors including GDF-11, EGF, FGF2, TGF-β1 and VEGF in order to prevent differentiation and increase stem cell proliferation. The fact that Applicant has potentially recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). The prior art suggests that both increased pluripotency and increased numbers of stem cells would result in increased numbers of exosomes released into the culture media. The prior art also suggests that exosomes have skin regeneration and wound healing properties. Therefore, a skilled artisan would expect that culture medium having increased numbers of exosomes would also have increased skin regeneration and wound healing properties. Additionally, as stated supra, Applicant has not supplied any measurements of released exosome concentration based on number of cultured stem cells, concentrations of growth factors, and timepoints in culture and Applicant’s claimed functional profile is based on extraction of exosomes and application of a particular concentration and not to the released exosome concentration.
Regarding unexpected results, Applicant traverses that the instant invention comprising culture of cord blood derived stem cells in “5GF” media produces alleged unexpected results including increased protein concentration in culture media, increased exosome number in culture media and uniform size of exosomes, improved migration and proliferation of dermal fibroblasts and keratinocytes, reduced apoptosis and inflammation which could not have been predicted by the prior art. Applicant asserts that the instantly claimed 5GF culture environment results in changes to exosome number, size uniformity, protein profile, and skin cell function which the prior art does not teach (Pg. 19-20, Section G).
Applicants traversal has been fully considered but is not persuasive.
As an initial matter, Applicant’s instant claims are drawn toward a method of culturing umbilical cord blood stem cells in serum-free media comprising GDF-11, EGF, FGF2, TGF-β1 and VEGF; all supplied at broad concentration ranges of 1-20 ng/mL; to produce a conditioned culture medium comprising exosomes. Based on the specification, in order to produce the conditioned culture medium, the cells must be cultured in the 5GF media for at least one day (Example 1). Further, claim 1 does not require method steps of isolating or concentrating exosomes in order to utilize isolated exosomes to examine the claimed functional effects. Thus, Applicant’s instantly claimed method is broadly drawn to methods of cell culture using growth factor conditioned media, but not to utilization of exosomes produced by the culture or any alleged unexpected effects of the exosomes. Although dependent claims 8 and 9 recite that the culture medium is formulated for a selected use, Applicant has not defined what is considered to be a selected use and has claimed no method steps directed to the use. Additionally, given the limited details of the specification and the breath of the claims, it is not clear that the alleged unexpected exosome phenotype is commensurate in scope with the instant claims. The method as instantly claimed is very broad and the specification does not provide details as to the number of cells in culture, the amount of time the cells are cultured, the specific concentration of growth factors present in the media, or the released exosome concentration at any timepoint in culture.
In regard to Applicant’s allegations of unexpected results, whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the “objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support”. In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980) (see MPEP 716.02(d). Further, a showing of unexpected results must be based on evidence, not argument or speculation. In re Mayne, 104 F.3d 1339, 1343-44, 41 USPQ2d 1451, 1455-56 (Fed. Cir. 1997) (conclusory statements regarding unusually low immune response or unexpected biological activity that were unsupported by comparative data held insufficient to overcome prima facie case of obviousness).
Although Applicant has supplied evidence related to alleged unexpected results of protein content in media, exosome number and uniform size, functional effects on fibroblast and keratinocyte proliferation, and prevention of apoptosis and inflammation, Applicant has supplied only a single figure for each comparison demonstrating the alleged unexpected result. Additionally, Applicant has not disclosed any of the culture parameters including number of cells, time in culture, or specific concentrations of growth factors corresponding to the culture conditions for each figure or each comparative example. Although Applicant has used the same number of extracted exosomes for functional effects on fibroblasts and keratinocytes (See Example 3 and 4), Applicant has likewise not disclosed the culture conditions related to production of the extracted and tested exosomes. Thus, Applicant has not shown that the alleged unexpected results occur over the entire claimed range which includes plating any number of cells, with all combinations of growth factors supplied at concentrations between 1-20 ng/mL, and cultured for all time points between 1 and 4 days.
In addition to the scope of the claims, the limited details in Applicant’s specification provides no ability to compare the instant results to that of the existing prior art. The specific details of Applicant’s disclosed culture method which Applicant asserts is responsible for the exosome phenotype would be required in order to make a comparison with the closest prior art. MPEP 716.02(b) states “Evidence of unexpected properties may be in the form of a direct or indirect comparison of the claimed invention with the closest prior art which is commensurate in scope with the claims”. In the instant case Applicant does not present a direct or indirect comparison with the closest prior art. Arguments of counsel cannot take the place of evidence where evidence is necessary (MPEP 716.01).
Furthermore, for at least the exosome number and size distribution, Applicant’s results appear to be expected. The prior art of Wolvetang discloses methods of maintaining the “stemness” or, conversely, preventing differentiation, of stem cells in culture, the prior art of Kern teaches that cord blood derived stem cells have higher expansion potential, the prior art of US ‘108 discloses use of media comprising growth factors to increase proliferation of cord blood derived stem cells, and the prior art of Kim teaches that cord blood derived stem cells release exosomes in culture. Therefore, a skilled artisan would expect that use of media components which are designed to maintain pluripotency and increase stem cell proliferation would also be likely to result in higher numbers of released exosomes based on increased numbers of exosome releasing cells. Regarding the instantly claimed uniform exosome size distribution, Kim discloses that exosomes from cord blood derived stem cells cultured in DMEM comprising 10 ng/mL of FGF2 and EGF (Pg 1103, left col., section 2.1) have a mean particle diameter of 120 nm (Pg. 1104, right col., 1st para) and exhibit a size distribution which appears similar to the instantly claimed size distribution (See below and Kim Fig. 3C(iii), Instant Fig. 2A). Thus, the instantly claimed exosome size and particle distribution appear to not only be expected based on the prior art, but also the same as exosomes from umbilical cord derived stem cells cultured in media comprising only two growth factors, FGF2 and EGF.
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Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Wolvetang, in view of Kern, US ‘108, and Kim as applied to claim 1 above and further in view Yeo et al. (2013, Mesenchymal stem cell: an efficient mass producer of exosomes for drug delivery. Adv. Drug Deliv. Rev., 65(3), 336-341, hereafter “Yeo”).
With regard to claim 5, which depends from claim 1, MPEP 2111.04 (II) indicates that he broadest reasonable interpretation of a method (or process) claim having contingent limitations requires only those steps that must be performed and does not include steps that are not required to be performed because the condition(s) precedent are not met. Claim 5 recites a contingent limitation wherein the exosomes have higher ability to regenerate the skin. Claim 1 does not recite method steps which include application of exosomes to the skin, therefore the ability to regenerate the skin is considered to be contingent on a method step which is not required by claim 1.
As detailed above and incorporated herein, the combined teachings of Wolvetang, Kern, US ‘108 and Kim teach culture of umbilical cord blood stem cells in serum free media comprising GDF-11, FGF2, EGF, TGF-β1, and VEGF in order to produce “conditioned” culture medium comprising exosomes at a concentration of 1 x 109 particles/ml. Wolvetang teaches that the culture medium comprising GDF-11 and FGF2 maintains stem cells in an undifferentiated state (Pg. 1, 2nd para.) which is important for the use of stem cells for therapeutic, clinical, or research purposes (Pg. 2, 3rd para.) and, further, that in the absence of appropriate culture conditions, stem cells will differentiate, losing pluripotent/multipotent potential, which results in a population of cells which is no longer useful for therapeutic, clinical, or research (Pg. 2, last para and Pg. 3, 1st two paras). Thus, Wolvetang’s culture media can be used to culture stem cells which retain “stemness”. US ‘108 teaches that growth factors EGF, TGF-β1, and VEGF promote proliferation of umbilical cord blood stem cells (Para. [0079]).
The combined teachings of Wolvetang, Kern, US ‘108, and Kim are silent as to comparison between exosomes from stem cells cultured in media comprising growth factors and exosomes from stem cells cultured in media without growth factors. However, Kim teaches that exosomes from UCB-MSCs and media comprising exosomes from UCB-MSCs, which were cultured in medium comprising EGF and FGF2 (Pg. 1103, Preparation of USC-CM) contain high concentrations of active proteins related to skin rejuvenation such as EGF and FGF2 (Pg. 1104, right col., last para.).
Yeo teaches that human mesenchymal stem cells (MSCs) are prolific producers of exosomes (Abstract, Fig. 2), have the potential to mass produce exosomes (Pg. 338, left col., 3rd para.), and can be derived from umbilical cord blood (Pg. 338, left col., 4th para.). Yeo teaches that MSCs differentiate into other cell types (Pg. 338, left col., 4th para.) and that although MSCs can be expanded, expansion is also finite leading to a need to constantly replenish the cell source of exosomes (Pg. 339, left col., 2nd para., lines 1-4).
Thus, based on the teachings of Wolvetang that stem cells can be cultured in media comprising GDF-11 and FGF2 such that they maintain “stemness” instead of differentiating, the teachings of US ‘108 that EGF, TGF-β1, and VEGF can promote proliferation of umbilical cord blood stem cells, and the teachings of Yeo that mesenchymal stem cells are prolific producers of exosomes for a limited amount of time, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, that the culture medium containing exosomes released by umbilical cord blood stem cells cultured in serum-free media comprising GDF-11, FGF2, EGF, TGF-β1, and VEGF as taught by the combined teachings of Wolvetang, Kern, US ‘108, and Kim would result in a greater number of released exosomes and thereby increased skin rejuvenation ability. A skilled artisan would have recognized that umbilical cord blood stem cells cultured by the method taught by Wolvetang, Kern, US ‘108, and Kim would maintain their stemness instead of differentiating, and thus would continue to release greater numbers of exosomes based on the teachings of Yeo.
Claims 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Wolvetang in view of Kern, US ‘108, and Kim as applied to claim 1 above and further in view of Mathen (WO2018150440, found in IDS dated 12/12/2024).
As detailed supra in the 112(b) rejections, Applicant has not defined what is to be considered “for a selected use”. Therefore, any use taught in the prior art is considered to read on a selected use.
With regard to claims 8 and 9, as detailed above and incorporated herein, the combined teachings of Wolvetang, Kern, US ‘108, and Kim teach culture of umbilical cord blood in serum free media comprising GDF-11, FGF2, EGF, TGF-β1, and VEGF in order to produce “conditioned” culture medium comprising exosomes at a concentration of 1 x 109 particles/ml. Kim further teaches use of the exosomes derived from umbilical cord blood stem cells for use in rejuvenation of skin (Abstract).
While the combination of Wolvetang, Kern, US ‘108, and Kim teaches regenerative use of exosomes derived from stem cells for skin, the combination of Wolvetang, Kern, US ‘and Kim are silent as to formulations of culture media comprising exosomes.
Mathen teaches a cell-free conditioned medium comprising factors secreted by human stem cells (Pg. 1, 1st para.) produced by cultivating stem cells in culture medium to allow secretion of factors including exosomes (Pg. 4, step (ii); Pg. 7, 1st & 2nd paras.) and subsequent harvesting of the “conditioned culture medium” (Pg. 4, step (iii)). Mathen teaches that the stem cells are human mesenchymal stem cells which can be derived from umbilical cord blood (Pg. 6, 2nd full para.). Additionally, Mathen teaches that the stem cell culture medium can comprise DMEM (Pg 9, 3rd full para.) and FGF2 (Pg. 5, 1st full para.; Pg 10, 2nd full para.) Further, Mathen teaches that the harvested conditioned medium (Pg. 11, 3rd para.) can be formulated for cosmetic or therapeutic applications by processes such as lyophilization (Pg. 12, 3rd para.), which is considered to reasonably read on dried to a power, or as a gel (Pg. 14, 1st full para.) as claimed in claim 9 and that conditioned media can be used for skin care and wound healing (Pg. 12, 1st para.) and applied topically (Pg. 12, last para.).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention to apply formulation of the conditioned culture medium comprising exosomes as taught by Mathen to the method of culturing umbilical cord blood stem cells in media supplemented with growth factors in order to produce culture medium comprising exosomes as taught by the combined teachings of Wolvetang, Kern, US ‘108, and Kim with a reasonable expectation of success. A skilled artisan would have been motivated to do this as Mathen teaches that culture media comprising exosomes secreted from stem cells can be lyophilized and used for cosmetic or therapeutic purposes and a skilled artisan would have easily recognized that lyophilization provides long-term storage ability of the therapeutic culture media. Further, a skilled artisan would have been motivated to formulate a composition into a gel in order to generate a composition which could be used topically, which is important for commercialization of a cosmetic or therapeutic product. Further, both Kim, which teaches use for skin rejuvenation, and Mathen, which teaches use for skin care and wound healing, teach culture media comprising exosomes for a selected use.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Wolvetang in view of Kern, US ‘108, and Kim as applied to claim 1 above and further in view of Casado-Díaz et al. (2020, Extracellular vesicles derived from mesenchymal stem cells (MSC) in regenerative medicine: applications in skin wound healing. Fron. in Bioeng. and Biotech., 8, 146., found in IDS dated 12/12/2024, hereafter “Casado-Diaz”).
With regard to claim 10, which depends from claim 1, MPEP 2111.04 (II) indicates that he broadest reasonable interpretation of a method (or process) claim having contingent limitations requires only those steps that must be performed and does not include steps that are not required to be performed because the condition(s) precedent are not met. Claim 10 recites a contingent limitation wherein the exosomes improve the migration and/or proliferation ability of human fibroblasts and/or human keratinocytes. Claim 1 does not recite method steps which include application of exosomes to human fibroblasts and/or keratinocytes, therefore the ability to improve the migration and/or proliferation ability is considered to be contingent on a method step which is not required by claim 1.
As detailed above and incorporated herein, the combined teachings of Wolvetang, Kern, US ‘108, and Kim teach culture of umbilical cord blood stem cells in serum free media comprising GDF-11, FGF2, EGF, TGF-β1, and VEGF in order to produce “conditioned” culture medium comprising exosomes at a concentration of 1 x 109 particles/ml.
Kim teaches use of exosomes derived from umbilical cord blood mesenchymal stem cells (UCB-MSCs) for use in rejuvenation of skin (Abstract). Kim further teaches that exosomes from UCB-MSCs and media comprising exosomes from UCB-MSCs contain high concentrations of proteins associated with skin rejuvenation such as EGF and FGF2 (Fig. 2 and Pg. 1104, right col., last para.) and that UCB-MSC exosomes at 1 x 109 particles/ml increased migration in human fibroblasts (Fig. 3D & 3E and Pg. 1105, right col., 1st para.). Additionally, Kim teaches that UCB-MSC exosomes exhibit skin rejuvenation ability and enhance growth and migration of human fibroblast cells (Pg. 1108, left col., 2nd and 3rd paras.). Thus, Kim teaches that UCB-MSC derived exosomes improve proliferation and migration of human fibroblasts.
Kim is silent as to the effect of UCB-MSC exosomes on keratinocytes.
Casado-Diaz teaches that exosomes derived from MSCs are able to activate proliferation and migration of the main cell types involved in skin regeneration, including fibroblasts and keratinocytes (Abstract). Casado-Diaz additionally teaches that MSCs derived from umbilical cord blood have been used for skin healing (Pg. 7, left col., 2nd para.).
Therefore, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to use exosomes released during culture of umbilical cord blood stem cells in media comprising GDF-11, FGF2, EGF, TGF-β1, and VEGF as taught by the combination of Wolvetang, Kern, US ‘108, and Kim and which are known to be able to improve proliferation and migration of human fibroblasts taught by Kim to the improve the proliferation and migration of keratinocytes as taught by Casado-Diaz with a reasonable expectation of success. Based on the teachings of Casado-Diaz and the combination of Wolvetang, Kern, US ‘108, and Kim, a skilled artisan would have every reason to believe that exosomes from umbilical cord blood stem cells cultured in media supplemented with GDF-11, FGF2, EGF, TGF-β1, and VEGF would improve the proliferation and migration of human keratinocytes, based on the teachings of Casado-Diaz and would have recognized that use of the exosomes released during culture of umbilical cord blood stem cells in media comprising GDF-11, FGF2, EGF, TGF-β1, and VEGF could be used to promote healing of the skin.
Response to Arguments
Applicant's arguments filed June 4, 2026 are acknowledged and have been fully considered but they are not persuasive.
Claim 5 was rejected under 35 U.S.C. 103 as being obvious over Wolvetang, Kern, and Kim in further view of US ‘108 and Yeo. Claims 8-9 were rejected under 35 U.S.C. 103 as being obvious over Wolvetang, Kern, and Kim in further view of Mathen. Claim 10 was rejected under 35 U.S.C. 103 as being obvious over Wolvetang, Kern, and Kim in further view of Casado-Diaz.
Regarding dependent claims 3 and 5-10, Applicant traverses that the additional references of Yeo, Mathen, and Casadio-Diaz are each general in nature and do not cure the deficiency related to the absence of teaching of culturing umbilical cord derived stem cells in the 5GF media composition and the functional profile of the produced exosomes.
Applicant’s traversal has been considered but is not persuasive. Applicant has not supplied additional arguments related to dependent claims 3 and 5-10. The traversal regarding the instantly claimed method of culturing umbilical cord derived stem cells in 5GF media and exosomes produced by such media are addressed supra.
Conclusion
No claims are allowed.
THIS ACTION IS MADE FINAL. 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.
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/ERIN V PAULUS/Examiner, Art Unit 1631
/ARTHUR S LEONARD/Examiner, Art Unit 1631
