DETAILED ACTION
Status of the Application
Receipt is acknowledged of Applicants’ Remarks, filed 26 February 2026, in the matter of Application N° 18/277,898. Said documents have been entered on the record. The Examiner further acknowledges the following:
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 18-49 are pending, where claims 21-49 remain withdrawn from consideration.
No claims have been added, amended, or canceled.
No new matter has been added.
Thus, claims 18-20 continue to represent all claims currently under consideration.
Information Disclosure Statement
No new Information Disclosure Statements (IDS) have been filed for consideration.
Maintained Rejections
The following rejections are maintained from the previous Office Correspondence dated 26 November 2025 since the art that was previously cited continues to read on the previously recited limitations.
Claim Rejections - 35 USC §101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
Claims 18-20 are rejected under 35 U.S.C. § 101 because the claimed invention is directed to laws of nature and natural phenomena without significantly more.
The claims recite laws of nature and natural phenomena. These judicial exceptions are not integrated into a practical application and the claims do not include additional elements that are sufficient to amount to significantly more than the judicial exception as explained below:
Subject Matter Eligibility Guidance
A three-step inquiry has been established to determine subject matter eligibility under 35 U.S.C. 101, in accordance with MPEP §2106:
PNG
media_image1.png
791
541
media_image1.png
Greyscale
PNG
media_image2.png
524
532
media_image2.png
Greyscale
Step (1): Is the claim directed to a process, machine, manufacture, or composition of matter?
Step (2A): Is the claim directed to a law of nature, natural phenomenon (product of nature), or an abstract idea?
Prong 1 – Does the claim recite a law of nature, natural phenomenon, or an
abstract idea?
Prong 2 – If the claim recites a judicial exception, does it recite additional elements that integrate the judicial exception into a practical application?
Limitations that are indicative of integration into a practical application include:
Improvements to the functioning of a computer, or to any other technology or technical field. See MPEP §2106.05(a)
Applying the judicial exception with, or by use of, a particular machine. See MPEP §2106.05(b)
Effecting a transformation or reduction of a particular article to a different state or thing. See MPEP §2106.05(c)
Applying or using a judicial exception to effect a particular treatment or prophylaxis for a disease or medical condition. See MPEP §2106.05(d)
Applying or using the judicial exception in some other meaningful way beyond generally linking the use of the judicial exception to a particular technological environment, such that the claim as a whole is more than a drafting effort designed to monopolize the exception. See MPEP §2106.05(e)
Step (2B): If the recited judicial exception is not integrated into a practical application, does the claim recite additional elements that amount to significantly different than the judicial exception such that they provide an inventive concept? This step includes evaluation of the same considerations under Step (2A), Prong 2, as well as two additional considerations:
Adding a specific limitation or combination of limitations that are not well-understood, routine, conventional activity in the field, which is indicative that an inventive concept may be present; and
Simply appending well-understood, routine, conventional activities previously known to the industry, specified at a high level of generality, to the judicial exception, which is indicative that an inventive concept may not be present.
Analysis
Step (1): The answer to this step is yes since claims 18-20 are directed to a composition of matter, which is a statutory category.
Step (2A): The answer to this step is yes because the claimed compositions are directed to laws of nature and natural phenomena, specifically naturally occurring mistletoe viscin and its compositional structural behaviors.
Prong 1:
Product of Nature Definition
When a law of nature or natural phenomenon is claimed as a physical product, the courts have often referred to the exception as a “product of nature.” See Ass’n for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. 576, 580, 106 USPQ2d 1972, 1975 (2013); University of Utah Research Foundation v. Ambry Genetics, 774 F.3d 755, 758-59, 113 USPQ2d 1241, 1243 (Fed. Cir. 2014). As explained in those decisions, products of nature are considered to be an exception because they tie up the use of naturally occurring things, but they have been labeled as both laws of nature and natural phenomena. See Myriad Genetics, Inc., 569 U.S. at 590-91, 106 USPQ2d at 1979.
Claim Analysis
Independent claim 18 recites “a self-supporting 2D mistletoe viscin film comprising a 2-dimensional multi-axial oriented array of viscin cellulose filaments within a matrix.”
The claim goes on to define “viscin” as “[referring] to a mucilaginous tissue surrounding pseudoseeds of mistletoe plants, the mucilaginous tissue comprising viscin cells exhibiting a characteristic cell wall structure of coiled cellulose fibrils and are organized in clusters or bundles in a natural humidity-responsive adhesive matrix.”
Claim 19 recites the natural sources from which the claimed viscin composition may be derived.
Claim 20 recites that the viscin cellulose filaments are locally oriented and embedded within the matrix and that “the matrix is humidity-responsive, the film exhibits adhesive properties in a hydrated/wet state and the film is non-adherent and transparent in a dehydrated/dry state.”
The Examiner acknowledges that the composition is styled in the preamble as being a “a self-supporting 2D mistletoe viscin film.” However, the scope, definition, and properties of the positively recited elements of the composition define it in terms of naturally-occurring compounds, and as such the film is defined as consisting of naturally-occurring compounds. Therefore, the instant claim recites a product of nature.
There is no evidence within the specification that the compositions recited in claims 18-20 contain markedly different characteristics from their naturally-occurring counterparts.
Therefore, the answer to step 2A prong 1 is yes.
Prong 2:
The Prong Two analysis considers the claim as a whole. That is, the limitations containing the judicial exception as well as the additional elements in the claim besides the judicial exception need to be evaluated together to determine whether the claim integrates the judicial exception into a practical application.
Here, the instantly amended claims do not introduce any additional limitations which transform or improve on the judicial exceptions recited in claims 18-20 and do not do anything beyond generally linking the use of the judicial exception to a particular technological environment.
Therefore, the answer to step 2A prong 2 is no.
Step (2B):
Claims 18-20 do not recite additional elements which require analysis under step 2B.
At most, claim 18 recites that the composition is directed to a composition comprising viscin cellulose filaments in an undefined matrix.
The state of the art additionally recognizes that naturally-occurring plant materials such as viscin as being the tissue of the European mistletoe plant Viscum album L. (see e.g., Azuma, of record; Abstract). See also Holbert et al. (Biomacromolecules; 2019, of record; Abstract).
Therefore, compositions comprising the instantly claimed ingredients, notably in topical formulations, and as pharmaceutical compositions, are well-understood as possessing routine, and conventional activity.
Therefore, the answer to step (2B) is no.
Conclusion
Claims 18-20 are directed to a judicial exception and do not qualify as eligible subject matter under 35 U.S.C. §101.
Response to Arguments
Applicants’ arguments with regard to the rejection of claims 18-20 under pre-AIA 35 USC 101 being directed to a natural product, have been fully considered, but are not persuasive.
Applicants initially allege that based on the 2025 guidance, “a claim reciting a natural material remains eligible where the claim, considered as a whole, reflects human-engineered structure and functional improvements rather than a mere natural product”. Applicants further assert that the Examiner’s conclusion that the claimed film lacks ‘markedly different characteristics’ from natural viscin is inconsistent with the record and with the very references the Office Action relies on for the anticipation rejections.
The Examiner, in response, respectfully disagrees and maintains that the instantly claimed composition is directed to a naturally-occurring product possessing no markedly different characteristics.
Revisiting the interpretation of the claimed composition, and considering the claim as a whole, the claim itself recites:
A self-supporting, 2D mistletoe viscin film comprising a 2-dimensional, multi-axial oriented array of viscin cellulose filaments within a matrix, wherein viscin, as used herein, refers to a mucilaginous tissue surrounding pseudoseeds of mistletoe plants, the mucilaginous tissue comprising viscin cells exhibiting a characteristic cell wall structure of coiled cellulose fibrils and are organized in clusters or bundles in a natural humidity-responsive adhesive matrix.
The broadest reasonable interpretation of the claimed is directed to a 2D film composed of the naturally-occurring material found in mistletoe berries. Applicants’ language within the claim itself is considered to affirm this position (see above emphases). The highlighted language is understood as describing natural features of viscin of mistletoe berries.
Regarding Step 2A, Prong 1, Applicants argue that “the cited art demonstrates that natural viscin does not exist as a multiaxially stretched or oriented film, an its microfibrils are not oriented in the manner required by the claims. Applicants further turn to the Azuma reference and state that it “shows that natural viscin contains tightly coiled cellulose microfibrils that only become aligned when mechanically stretched.”
Similarly, Applicants argue that Holbert “likewise confirms that viscin’s fibrillar orientation arises only through human-applied mechanical drawing. Natural viscin does not exhibit such orientation.”
The Examiner disagrees and submits that Applicants’ position is predicated on the notion that humans are the only source capable of manipulating the berries. The Examiner notes that both references disclose that mistletoe berries (i.e., the source of the naturally-occurring viscin) serve as food for birds. Azuma states that “[u]pon disruption of the berry, as for instance in a bird gut, the easily stretchable viscin tissue pulls out of the endosperm sac and consequently the entrapped seed” (see pg. 9, lines 7-9). Holbert discloses that “[b]irds rapidly swallow a couple of whole berries, which pass through the digestive system within minutes and are excreted onto lower branches onto which the viscin adhesive glues the seed” (see pg. 3094, right col., lines 7-10).
Thus, the art of record establishes that natural masceration and digestion of mistletoe berries also leads to the manipulation of and stretching of viscin tissue. In fact, both articles state that one of the reasons for experimenting with the tissue is because of the observed natural characteristics revealed by birds’ interaction with the berries.
Thus, the answer to Step 2A, Prong 1, remains “yes”.
Regarding Step 2A, Prong 2, Applicants assert that the claims apply human intervention to create non-naturally occurring structural and functional characteristics, including:
a self-supporting two-dimensional film not found in nature;
a multi-axial oriented array of filaments that are locally aligned due to applied mechanical loads, as described in the specification (see e.g., pg. 4, lines 5-10);
humidity-responsive behaviors engineered to produce reversible adhesion and transparency transitions (claim 20); and
suitability for technical applications such as biomedical scaffolding.
Applicants assert that these features provide practical, technological benefits, that distinguish the claimed film from unprocessed viscin and demonstrating an integration into a practical technological application, which is one of the central considerations of the USPTO’s 2025 guidance.
The Examiner, in response, respectfully disagrees and maintains that the references speak to the naturally-occurring aspects that Applicants attest are “man-made”.
Items i.) and ii.) are already discussed above as being accomplished in nature as not necessarily being done by the hand of man (i.e., avian consumption, digestions, and deposition).
Item iii.) is also discussed by both references insomuch that stimuli such as humidity and moisture levels directly impact the mobility and adhesion of the naturally-occurring viscin material. Azuma, for instance, discloses that “[w]hen the tissue is hydrated, these microfibrils are free to slide past one another thanks to the wet hemicelluloses that act as a lubricant” (see pg. 17, lines 1-3). Holbert on the other hand discloses that “[w]hile the gelatinous layer surrounding the seed remains rather sticky for several hours, the fibers lose their viscous, adhesive character after only a few minutes of drying under ambient conditions and become quite stiff but remain flexible in bending and twisting” (see pg. 3097, lines 3-7).
Thus, what is understood from these disclosures is that naturally-occurring humidity stimuli are being reproduced experimentally to reproduce and study viscin’s naturally-occurring adhesive properties.
Lastly, item iv.), were it part of the claims at issue as discussed, would be broadly and reasonably considered as being directed to an intended use of the naturally-occurring film that results from the viscin tissue.
Thus, the answer to Step 2A, Prong 2 remains “no”.
Regarding Step 2B, Applicants argue that “the claimed film’s structural transformations and engineered orientation angles constitute markedly different characteristics compared to natural viscin. As Azuma and Holbert confirm, natural viscin does not exhibit such structure or properties absent directed processing. The claimed configuration is therefore a man-made improvement over natural materials, and not merely an observation or isolation of a natural phenomenon.”
The Examiner, in response, respectfully disagrees and maintains, consistent with the foregoing disclosures and discussion of the references, that the alleged man-made improvements are, in fact, reproductions of the naturally-occurring phenomena of the viscin material and that Applicants’ manipulation and production of a film does not amount to anything demonstrating “significantly more” than the natural product used to produce these features.
As such, the answer to Step 2B remains “no”.
Thus, for these reasons, Applicants’ arguments are found unpersuasive. The above rejection is hereby maintained.
Claim Rejections - 35 USC §102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 18-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Azuma et al. (Cellulose, 2000; IDS reference of record).
The limitations of claim 18 are directed to a two-dimensional film comprising a two-dimensional, multi-axial-oriented array of viscin cellulose filaments within a matrix. As defined by Applicants in the claim, viscin is referred to as “a mucilaginous tissue surrounding pseudoseeds of mistletoe plants, the mucilaginous tissue comprising viscin cells exhibiting a characteristic cell wall structure of coiled cellulose fibrils and are organized in clusters or bundles in a natural humidity-responsive adhesive matrix.”
Azuma discloses that viscin is derived from mistletoe berries of Viscum album L. (see e.g., Title, Abstract). Each mistletoe berry is taught as containing a mucilaginous tissue, called viscin, that consists of cellulose in a mixture of acidic and neutral polysaccharides (matrix). The composite substance has a sticking property. In the elongated viscin cells of Phthirusa pyrifolia, the cellulose microfibrils are tightly coiled (multi-axial) with their axes rigorously perpendicular to the long dimension of the cell. One of the extraordinary features of viscin cells is that they can be readily stretched and that during such stretching, the cellulose microfibrils contained in the wall of the viscin cells get uncoiled and become aligned with their axes parallel to the stretching direction (see pg. 4, first full paragraph).
The Examiner thus interprets the pre-stretched viscin material of the mistletoe berries to anticipate the instantly claimed composition. Therein, the pre-stretched material is expressly disclosed as being multi-axial and contained within a polysaccharide matrix.
The material is further expressly disclosed as being sourced from Viscum album L., thereby meeting claim 19. The material is also expressly disclosed as being sticky or adhesive; such is taught as being vital for propagating the species. Lastly, the containment of the coiled (multi-axial) microfibrils within the berry is considered to meet the limitations of claim 20 reciting that the viscum cellulose filaments are locally oriented and embedded within the matrix and the material is taught as possessing a sticky property.
As such, the reference is considered to teach each of the instantly claimed limitations.
Response to Arguments
Applicants’ arguments with regard to the rejection of claims 18-20 under pre-AIA 35 USC 102(a)(1) as being anticipated by Azuma have been fully considered, but are not persuasive.
Applicants traverse the rejection on two grounds.
Firstly, Applicants assert that “the claimed invention is directed to a viscin film, whereas the viscin material disclosed in Azuma cannot be regarded as a film prior to stretching, since only stretching leads to a film within the meaning of the present invention.”
The Examiner finds this line of traversal unpersuasive as the reference expressly discloses stretching the material.
Secondly, Applicants content that viscose film in claim 18 is not perfectly molecularly aligned after stretching, but exhibits a two-dimensional, multi-axially aligned grouping of viscose cellulose filaments in a matrix. Applicants attempt to contrast this with the teachings of Azuma by implying that Azuma discloses stretching in only one direction whereas the instant invention forms a film by stretching the material in more than one direction.
Here, the Examiner submits that Azuma teaches that the microfibrils “are aligned with respect to the filament axis, but on the filament edge, some microfibrils are pulled out and adopt a different and somewhat relaxed orientation” (see pg. 13, lines 10-12). The reference additionally teaches that “[d]uring such deformation, the tight cellulose winding of tangential cellulose microfibrils gets deformed to the point where all the microfibrils become oriented along the deformation direction” (see pg. 11, lines 9-11). This implies that microfibrils will be deformed in the direction of in which they are pulled.
Thus, for these reasons, Applicants’ arguments are found unpersuasive. The above rejection is hereby maintained.
Claims 18-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Holbert et al. (Biomacromolecules; 2019, IDS reference of record).
The limitations of claims 18-20 are discussed above.
Holbert discloses mucilaginous viscin tissue within mistletoe berries having two-dimensional multi-axial array (see e.g., Abstract and Figure 3A). These berries possess the ability to be rapidly processed under ambient conditions into stiff cellulosic fibers through simple mechanical drawing (see e.g., Abstract).
In considering the disclosed mechanical drawing, the Examiner considers this processing step as well as the mucilaginous viscin tissue to read on the instantly claimed composition, notably in view of the definition provided in the instant specification depicting what it means to mechanically draw the seed from the fruit skin.
As defined by the instant specification, Figure 2A appears to depict this process as producing a viscin film substance:
PNG
media_image3.png
278
278
media_image3.png
Greyscale
See also Figure 3A-3F which defines the “film” as being produced from the viscin found directly within the mistletoe berry. Thus, based on Applicants’ definition in the instant specification, showing of the viscum material obtained from mistletoe berries is considered to produce the instantly claimed film. See MPEP §2111.
Holbert further discloses analyses of berries from V. album and the distantly related species Phthirusa pyrifolia reported that formation of mistletoe fibers emerges from specific bundles of elongated cells known as viscin cells that are embedded within the mucilaginous tissue surrounding the seed. In both species, these cells possess an irregular cross-sectional shape with massive cell walls and small central lumen, in which cellulose fibrils are arranged in an unusual manner, perpendicular to the cell long axis by an angle close to 90º (see pg. 3094, paragraph bridging pp. 3094-3095).
The Introduction further discloses the adhesive nature of viscum disclosing that it has been traditionally used to produce birdlime, a natural glue made from mistletoe berries, which was spread (i.e., formed into a film) on branches to capture birds since ancient times (see pg. 3094, left col.). Such is considered to teach the recited natural adhesion property in claims 18 and 20.
Transition from an aligned, yet flowing state to a stiff fiber is likely triggered by water loss below 45% relative humidity (RH) (see e.g., Abstract). Such is considered to expressly teach that the material is humidity-sensitive. The foregoing is considered to teach that it is adhesive when used in a glue (semi-liquid state) format.
The foregoing is thus considered to meet the limitations of the instantly claimed composition.
Response to Arguments
Applicants’ arguments with regard to the rejection of claims 18-20 under pre-AIA 35 USC 102(a)(1) as being anticipated by Holbert et al. have been fully considered, but are not persuasive.
Applicants traverse the rejection on the grounds that “Holbert discloses the stretching of the viscous material in only one direction … and by no means further stretching in (at least) a second direction.”
The Examiner, acknowledges that the experimental methods employed in the reference may not disclose stretching in a second direction. However, the opening introduction to the naturally-occurring material at issue is discussed as being studied due to the observation in nature of its use as a mucilaginous glue: “[d]ue to its adhesive nature, viscin was traditionally used to produce birdlime (Latin: viscum), a natural glue made from mistletoe berries, which was spread on branches to capture birds since ancient times” (see pg. 3094, left col., last full sentence). That the naturally-occurring material was known to be spread on a three-dimensional structure such as branch is considered to expressly disclosed stretching viscum in more than two dimensions, thereby creating a naturally-adhesive film on branches.
Thus, for these reasons, Applicants’ arguments are found unpersuasive. The above rejection is hereby maintained.
All claims under consideration remain rejected; no claims are allowed.
Conclusion
THIS ACTION IS MADE FINAL. Applicants are 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 extension fee 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.
Correspondence
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to Jeffrey T. Palenik whose telephone number is (571) 270-1966. The Examiner can normally be reached on 9:30 am - 7:00 pm; M-F (EST).
If attempts to reach the Examiner by telephone are unsuccessful, the Examiner’s supervisor, Robert A. Wax can be reached on (571) 272-0623. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/Jeffrey T. Palenik/
Primary Examiner, Art Unit 1615