DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on March 18, 2026 has been entered.
Claim Rejections - 35 USC § 112
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.
Claims 22 and 25-31 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 22 recites “single layered blood product…wherein the single layered blood product comprises a first surface region and a second surface region opposite the first surface region, wherein the first surface region has a higher concentration of fibrin than the second surface region opposite the first surface region, wherein the second surface region has a higher concentration of platelets than the first surface region [emphasis added]”. As discussed in the rejection detailed below under section (b) of this statute, the structure that corresponds to a “single layered” product is not clear, given the required stratification of the product components. Even if the ‘single layered’ aspect is viewed as embracing the required stratification, it is not clear that the applicant contemplated the method where fibrin and platelets isolated from whole blood are polymerized in three dimensions and compressed into the product with the spatial arrangement of the fibrin and platelets that is also required. This is particularly an issue when the compression is performed by centrifugation, as required in instant claim 30. Specifically, a process that arranges fibrin and platelets in the blood product where a pair of opposing surface regions have high platelet concentration and low fibrin concentration on one surface while having low platelet concentration and high fibrin concentration in the opposite surface regions via polymerizing fibrin and platelets in three dimensions and compressing the fibrin is not described. Some details of possible centrifugation speeds and times for whole blood are detailed, but none are linked with producing the instantly claimed arrangement of components (see pages 15-19). The instant examples point to prior art methods of producing fibrin containing blood products, where the blood components are stratified, but none explicitly describe the distribution of fibrin and platelets through the thickness/depth of the final product. Bai et al. (Clinics 2017 72(2):116-124) detail centrifugation of platelet rich plasma extracted from whole blood. After their regimen of 10 minutes of centrifugation with a g-force due 3000 RPM in their chosen centrifuge, the fibrin and platelets form a polymerized mass with the fibrin and platelets stratified such that both are at high concentration on one surface and low concentration on the opposing surface (see page 117 first column last partial paragraph-second column first partial paragraph and figures 4-5). The higher concentration of fibrin corresponds to lower porosity/pore size (see figures 4-5). Additionally, Grippi et al. (US PGPub No. 2011/0020196) teach a fibrin network/membrane for various clinical application made by centrifugation of platelet rich plasma which includes both fibrin and platelets in a manner taking advantage of the differing sedimentation behaviors of fibrin and platelets (see paragraph 160 and 170-176). They detail that the location of the platelets in the network/membrane can be controlled so as to localize them to a desired location in effort to produce a desired interaction with patient tissue upon implantation (see paragraph 176). They note that platelets move through the plasma at a constant velocity that can be increased by increasing g-force but that fibrin formation/coagulation occurs independently of this g-force (see paragraph 171). They teach that centrifugation at 4000 to 6000xG immediately after exposure of the plasma to a coagulation initiator quickly sediments platelets through the plasma in the initial 5 to 10 minutes while the fibrin takes 25-30 minutes to fully form (see paragraph 173). The result is a concentration of platelets at the surface of the fibrin that initially formed and lower platelet density in the subsequent layers//regions of fibrin formed later as the fibrin formed/coagulated (see paragraph 173). They detail another centrifugation regimen where a lower g-force is employed and results in a uniform distribution of platelets, since the platelet sedimentation velocity more closely matched the rate of fibrin formation (see paragraph 174). Grippi et al. also detail that oscillation of higher and lower g-force centrifugation periods can produce alternating layers of platelet concentrations through the depth of fibrin that forms (see paragraph 175). Grippi et al. do not discuss the distribution of fibrin in their structures that form. The “written description requirement may be satisfied through disclosure of function and minimal structure when there is a well-established correlation between structure and function. In contrast, without such a correlation, the capability to recognize or understand the structure from the mere recitation of function and minimal structure is highly unlikely” (see MPEP 2163 II(A)(3)(a)(i)). Here, the applicant has not disclosed the steps to obtain the required structure within the constraints of the method steps that are also required and the prior art does not appear to fill in the descriptive gap. Therefore the artisan of ordinary skill would not have deemed the applicant to be in possession of the invention as instantly claimed.
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 22 and 25-31 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 22 recites a “single layered blood product…wherein the single layered blood product comprises a first surface region and a second surface region opposite the first surface region, wherein the first surface region has a higher concentration of fibrin than the second surface region opposite the first surface region, wherein the second surface region has a higher concentration of platelets than the first surface region [emphasis added]”. The structure that is permitted by the recitation “single layered” is unclear. The sole example described as producing a single layer material in the instant specification coagulates human plasma then physically compresses the material into “a single layer patch” (see instant specification example 1). The plasma is not recited to contain platelets and the instant specification describes plasma as acellular, thus this material was not clearly meet the limitations of the instantly claimed platelet containing product (see page 2 line 15). Two other examples prepare blood products according to US Patent No. 8,980,301 by Lundquist et al. This reference describes various embodiments of what it names “multilayered blood products” generated from centrifuging whole blood via particular techniques in a particular device and capturing particular coherent sections that have stratified regions of blood components (see instant specification examples 2-3 and Lundquist et al. examples 1-5). These regions have high concentrations of different blood components that have separated due to their differing densities, as permitted by the viscoelastic properties of the surrounding material during centrifugation. The final example in the instant specification, example 4, prepares a blood product via the procedure of WO 2010/020254 which is the parent PCT of Lundquist et al. and therefore also describes various embodiments of what it names “multilayered blood products” generated from centrifuging whole blood. Instant claim 22 recites a single layered product that is stratified such that opposing surfaces have different platelet and fibrin concentrations that are quantitatively opposite (e.g., platelet concentration is high where fibrin concentration is low and vice versa). Such required stratification, when present in the exemplary blood product preparations in the specification, is entitled “multilayered”. This then makes similar stratification in the product produced by the instantly claimed steps contradict the product simultaneously being claimed as “single layered” in the claim preamble. Thus it is unclear which arrangements of components are required and permitted in the ‘single layered’ blood product made and employed in the instantly method claimed.
Relevant Prior Art
Grippi et al. teach a fibrin membrane/network generated from concurrent centrifugation and coagulation of a patient’s own platelet rich plasma (see paragraphs 81, 91, and 131). They teach the membrane as a holding and separating structure for dental and general surgery (see example 5). The surface area of the membrane is determined by the radius of the container employed for centrifugation where membrane diameters of up to, but not limited to, 1000 mm are envisioned (see paragraphs 131-139). Membrane thickness can be controlled by design features of the centrifugation container as well as centrifugation conditions, where a 24 mm diameter and 3 mm thick (width-to-length ratio of 8) example is illustrated (see paragraphs 139 and 152 example 5). Grippi et al. detail that the location of the platelets in the network/membrane can be controlled so as to localize them to a desired location in effort to produce a desired interaction with patient tissue (see paragraph 176). They teach the utility of a membrane, with a concentration of platelets on one surface that diminishes through the thickness of the membrane (see paragraphs 170 and 173). Specifically they teach the membrane to be useful when the surface with concentrated platelets is placed facing a tissue wound/defect to increase vascularization and adhesion at the interface location (see paragraphs 170 and 173).
Delmotte C (WO 96/22115 – previously cited) detail employing crosslinked fibrin membranes as anti-adhesion barriers between tissues (see page 1 lines 16-21 and page 3 line 22-page 4line 3). They detail a graded porosity/pore size of the fibrin as beneficial, where a large pore containing layer encourages blood entry and tissue integration from a wound and an overlying small pore containing layer inhibits both interactions and acts as an anti-adhesive fibrin surface for a tissue surface that would otherwise be in contact with the wound (see page 14 line 10-page 15 line 15 and page 17 lines 6-29).
Bai et al. detail centrifugation of platelet rich plasma extracted from whole blood where a membrane with stratified and compressed fibrin results such that it has a high concentration on one surface and low concentration on the opposing surface (see page 117 first column last partial paragraph-second column first partial paragraph and figures 4-5). The higher quantity/concentration of fibrin corresponds to lower porosity/pore size (see figures 4-5).
When considered together, Grippi et al. and Delmotte C show that a gradation of fibrin porosity/pore size and platelet concentration in a fibrin membrane were known to be beneficial for application to wounded surfaces, where a large pore size (low fibrin concentration) and high platelet concentration at the wound surface is desirable. Delmotte C points to such membranes acting as anti-adhesion barriers via a small pore size (low concentration) fibrin surface. Thus the instantly claimed structure and the method of preventing adhesions via its application were obvious from the prior art. Bai et al. teach that the fibrin pore size/concentration gradation is attainable via centrifugation. However, the evidence of record is currently unclear as to the details of simultaneous polymerizing and compressing that achieves the claimed structure and the fate of the fibrin structure when the polymerizing and compressing via centrifugation (e.g., Grippi et al.) is sufficient to yield the claimed platelet distribution.
Response to Arguments
Applicant's arguments filed March 18, 2026 have been fully considered. In light of the amendment to the claims, the previous grounds of rejection are withdrawn and new grounds of rejection are presented in their place.
Conclusion
No claims is allowed.
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/CARALYNNE E HELM/ Examiner, Art Unit 1615
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