Ex Parte Nies et al

Board of Patent Appeals and Interferences

May 1, 2012

10918743 (B.P.A.I. May. 1, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte BERTHOLD NIES, ANDREAS SEWING,
DIETER SCHARNWEBER, HARTMUT WORCH, and
RENE BEUTNER
__________

Appeal 2011-009322
Application 10/918,743
Technology Center 1600
__________

Before MELANIE L. McCOLLUM, JEFFREY N. FREDMAN, and
STEPHEN WALSH, Administrative Patent Judges.

FREDMAN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to a process
for preparing a chitosan coated metallic article. The Examiner rejected the
claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.

Appeal 2011-009322
Application 10/918,743

2
Statement of the Case
Background
“The invention relates to a metallic article having a stable coating of
chitosan and to a process for the production thereof. The incorporation of
biologically active components into the chitosan coating enables the latter to
be matched to a very wide variety of applications and the biocompatibility of
correspondingly modified surfaces to be increased” (Spec. 1, ll. 3-7).
The Claims
Claims 4, 8, 14-19, 21, 22, 26-31, and 33 are on appeal. Claims 15
and 21 are representative and read as follows:
15. A process for preparing an impermeable, metallic,
chitosan coated article having a barrier action, wherein
the chitosan coating is solely directly present on the
metal,
comprising
cathodically polarizing the metallic article in a
chitosan-containing solution, which is an aqueous,
weakly acidic solution with an organic or inorganic acid,
wherein the polarization is carried out galvanostatically
with a current density of 0.1 to 20 mA cm-2, and to a cell
potential of 5 to 150 V, whereby said chitosan coating
solely directly present on the metal is achieved.

21. A process for preparing an impermeable, metallic,
chitosan coated article having a barrier action, wherein
the chitosan coating is directly present on the metal,
comprising
cathodically polarizing the metallic article in a
chitosan-containing solution, which is an aqueous,
weakly acidic solution with an organic or inorganic acid,
wherein the polarization is carried out galvanostatically
with a current density of 0.1 to 20 mA cm-2, and to a cell
potential of 5 to 150 V, and
Appeal 2011-009322
Application 10/918,743

3
wherein one or more biologically active
components are added to the chitosan-containing solution
with the proviso that collagen and glycosaminoglycan are
exempt from being said one or more biologically active
components.

The issues

A. The Examiner rejected claims 4, 8, 14-19, 21, 22, 26-31, and 33 under
35 U.S.C. § 103(a) as obvious over Lopez Lacomba,1 Redepenning,2
Worch,3 and Geibler4 (Ans. 4-7).
B. The Examiner rejected claims 21, 22, and 27-31 under 35 U.S.C. §
103(a) as obvious over Lopez Lacomba, Redepenning, Worch, Buirge5 and
Akiyama6 (Ans. 7-9).
A. 35 U.S.C. § 103(a) over Lopez Lacomba, Redepenning, Worch, and
Geibler
The Examiner finds that “Lopez Lacomba et al. teach the application
of a chitosan coating with biological activity to the surface of metallic
medical devices to confer improved cell adhesion” (Ans. 4). The Examiner

1 Lopez Lacomba et al., US 2003/0124172 A1, published Jul. 3,
2003.
2 Redepenning et al., US 2002/0084194 A1, published Jul. 4, 2002.
3 Worch et al., US 6,524,718 B1, issued Feb. 25, 2003.
4 Geibler et al, Collagen type I-coating of Ti6Al4V promotes
adhesion of osteoblasts, 51 J. BIOMEDICAL MATERIALS RESEARCH
752-760 (2000).
5 Buirge et al., US 5,693,085, issued Dec. 2, 1997.
6 Akiyama et al., Analysis of Fibronectin Receptor Function with
Monoclonal Antibodies: Roles in Cell Adhesion, Migration,
Matrix Assembly, and Cytoskeletal Organization, 109 J. CELL
BIOLOGY 863-875 (1989).
Appeal 2011-009322
Application 10/918,743

4
finds that “Redepenning teaches a method of applying a chitosan coating
onto a titanium substrate by cathodically polarizing the metal at a current of
10 mA/cm2 in a solution with 2.5% chitosan and 5% acetic acid” (Ans. 5).
The Examiner finds that “Worch et al. teach a method of depositing collagen
onto a titanium alloy surface by the application of galvanostatic polarization
using a current density of 3 mA/cm2 up to a potential of 40V” (Ans. 6). The
Examiner finds that “Geibler et al. teach tropocollagen and type I collagen as
proteins that promote the adhesion of osteoblasts to titanium alloy, a
material which along with titanium, is commonly used in bone implant
applications” (Ans. 6).
The Examiner finds it obvious to use the Redepenning “method as the
chitosan application step in Lopez Lacomba et al. In the case of chitosan, its
electrical resistance is higher than that of the electrode itself. So as the
thickness of the higher resistance deposition layer increases during the
constant current deposition process, the voltage increases (up to some
limiting value)” (Ans. 6). The Examiner finds that “[s]ince it was known
that the voltage in the system is a function of the coating thickness, it would
have been obvious to stop the application of current when a particular
voltage and coating thickness had been reached” (Ans. 6).
Appellants contend that “it was indeed truly unexpected that chitosan
is able to form an impermeable coating on a metallic article by polarization
applying the parameters as set forth in the claims of the present application”
(App. Br. 4). Appellants contend that “the present process is not obvious
over Redepenning alone or combination with the remaining references”
(App. Br. 6).
Appeal 2011-009322
Application 10/918,743

5
Appellants contend that:
Redepenning does not relate to an electrodeposition of
chitosan directly on a metallic surface. This is in particular
true since the small calcium phosphate molecules are
preferably transported through the electrolyte solution and
thus are deposited on the metallic surface before the rather
large chitosan molecule, which is transported rather slowly
due to its size and multiple charges distributed over the
whole molecule.

(App. Br. 7). Appellants contend that it “was by no means predictable for a
person skilled in the art at the time the application was filed that it is
possible to apply a cathodic polarization process for depositing chitosan onto
a metallic surface” (App. Br. 8). Appellants contend that this “is clear
simply by looking at the structure of chitosan. A person skilled in the art
would expect that chitosan would hardly adhere to a metallic surface
due to its rather unpolar nature” (App. Br. 8).
The issue with respect to this rejection is: Does the evidence of record
support the Examiner’s conclusion that Lopez Lacomba, Redepenning,
Worch, and Geibler render claims 15 and 21 obvious?
Findings of Fact
1. Lopez Lacomba teaches “a chitosan-based film totally or
partially coated product, such as an implant of dental or traumatologic use”
(Lopez Lacomba 2 ¶ 0021).
2. Lopez Lacomba teaches a “fragment of a titanium screw used in
the trials of implants in experimental animals, coated with a chitosan film
stabilized with NaOH and submitted to a treatment of activation” (Lopez
Lacomba 3 ¶ 31).
Appeal 2011-009322
Application 10/918,743

6
3. Lopez Lacomba teaches:
a method for the production of a chitosan-based film with
increased capacity for cell adhesion, hereinafter the method
of the invention, which comprises:
a) dissolving chitosan, optionally along with a
biodegradable polymer, in a solubilization medium
comprising an aqueous solution of an acid;
b) depositing the solution resulting from step a) on a
surface;
c) drying the solution deposited on the surface, in
order to obtain a chitosan-based film;
d) bringing the chitosan-based film into contact with a
stabilization agent selected from (i) an aqueous solution of a
base, (ii) a pH buffer equal to or greater than 5, (iii) a link-
forming agent, and (iv) mixtures thereof
e) washing the stabilized chitosan-based film obtained
in step d); and
f) drying the stabilized and dried chitosan-based film.

(Lopez Lacomba 3-4 ¶¶ 0040-0046).
4. Redepenning teaches that “composite coatings wherein the
separate species are deposited simultaneously can be deposited on the
cathode utilizing a current density of from about 1 mA/cm2 to about 1
A/cm2, preferably from about 10 mA/cm2 to about 100 mA/cm2”
(Redepenning 4 ¶ 0033).
5. Redepenning teaches that:
After the brushite coating was deposited onto the cathode,
the electrolyte solution was removed from the apparatus and
replaced with a second electrolyte solution comprising
chitosan (2.5% by weight) and acetic acid (5% by weight) . .
. A current was passed between the anode and the cathode
(10 mA/cm2) for about 60 seconds to deposit a chitosan
coating onto the brushite coating on the cathode.

Appeal 2011-009322
Application 10/918,743

7
(Redepenning 6 ¶ 0051).
6. Redepenning teaches that a “calcium phosphate containing
solution (200 mL) and the chitosan containing solution (10.5 mL) were then
mixed together to form a calcium phosphate electrolyte containing about
0.008 M chitosan” (Redepenning 6 ¶ 0056).
7. Redepenning teaches that after “the apparatus was filled with
the electrolyte, current was passed between the anode and the cathode (50
mA/cm2) for a period of about 5 minutes to co-deposit a coating of brushite
and chitosan on the cathode” (Redepenning 6 ¶ 0057).
8. Redepenning teaches that “hydroxyapatite is known to be
biocompatible and has been shown to enhance both interfacial shear strength
and bone contact when utilized with implant materials such as titanium or
other conductive metal alloys” (Redepenning 1 ¶ 0003).
9. Redepenning teaches that the “incorporation and intermingling
of chitosan in the resulting composite coating on the cathode reduces the
amount of surfaces defects found in a neat brushite or hydroxyapatite
coating by ‘filling in’ surface voids” (Redepenning 4 ¶ 0034).
10. Worch teaches
a method for deposition of bioactive coatings on conductive
substrates. An electrolytic cell contains an inert anode and
an electrolyte solution, which consists of an aqueous
solution of ions of the ceramic and exhibits a pH-value of
less than 8. The activated conductive substrate is immersed
into the electrolyte solution and the potential between anode
and conductive substrate set such that a ceramic coating is
deposited on the conductive substrate

(Worch, col. 2, ll. 1-9).
Appeal 2011-009322
Application 10/918,743

8
11. Geibler teaches that ten “minutes after plating, about 60 or 90%
of the cells became adherent to titanium alloy coated with monomeric or
fibrillar collagen, respectively. The number of cells adherent to uncoated
titanium alloy reached after 10 min about 30% of the initial cell number”
(Geibler 755, col. 2).
Principles of Law
Claim terms are interpreted using the broadest reasonable
interpretation in light of the Specification. See, e.g., In re Hyatt, 211 F.3d
1367, 1372 (Fed. Cir. 2000) (“[D]uring examination proceedings, claims are
given their broadest reasonable interpretation consistent with the
specification.”).
“The combination of familiar elements according to known methods
is likely to be obvious when it does no more than yield predictable results.”
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).
In cases involving overlapping ranges, we and our
predecessor court have consistently held that even a slight
overlap in range establishes a prima facie case of
obviousness …. The normal desire of scientists or artisans to
improve upon what is already generally known provides the
motivation to determine where in a disclosed set of
percentage ranges is the optimum combination of
percentages.

In re Peterson, 315 F.3d 1325, 1329-1330 (Fed. Cir. 2003).
[W]here the Patent Office has reason to believe that a
functional limitation asserted to be critical for establishing
novelty in the claimed subject matter may, in fact, be an
inherent characteristic of the prior art, it possesses the
authority to require the applicant to prove that the subject
matter shown to be in the prior art does not possess the
Appeal 2011-009322
Application 10/918,743

9
characteristic relied on.… Whether the rejection is based on
“inherency” under 35 U.S.C. § 102, on “prima facie
obviousness” under 35 U.S.C. § 103, jointly or alternatively,
the burden of proof is the same, and its fairness is evidenced
by the PTO's inability to manufacture products or to obtain
and compare prior art products.

In re Best, 562 F.2d 1252, 1254-55 (CCPA 1977).
Analysis
Claim 15
Beginning with claim interpretation, claim 15 expressly recites that
“the chitosan coating is solely directly present on the metal” (Claim 15). We
therefore interpret claim 15 as requiring that there is no intermediary
between the chitosan and the metal when prepared by the method of claim
15.
Lopez Lacomba teaches a method of coating a titanium screw with a
chitosan film which does not incorporate any other coating (FF 1-2), but the
process used by Lopez Lacomba is not galvanic, but rather involves
deposition of chitosan onto the metal (FF 3). Redepenning teaches
deposition of a composite coating of hydroxyapatite and chitosan onto a
metal using an electrical current (FF 4), but Redepenning always teaches
that the chitosan is co-deposited with brushite in a composite coating, either
by precoating the metal with brushite (FF 5) or when the chitosan and
calcium phosphate are deposited together (FF 6-7). Redepenning teaches a
range of current densities which overlaps the claimed range of 0.1 to 20
mA/cm2 (FF 4).

Appeal 2011-009322
Application 10/918,743

10
Applying the KSR standard of obviousness to the findings of fact, we
agree with the Examiner that an ordinary artisan would have reasonably
found it obvious to modify the coating method of Lopez to use the current
deposition method of Redepenning (see Ans. 6). There is a more than
reasonable expectation of success in this combination since Lopez Lacomba
demonstrates that chitosan can be deposited on a metal surface (FF 2-3) and
Redepenning teaches that chitosan may be deposited on surfaces using
current deposition. Such a combination is merely a “predictable use of prior
art elements according to their established functions.” KSR, 550 U.S. at 417.
Appellants contend that “it was indeed truly unexpected that chitosan
is able to form an impermeable coating on a metallic article by polarization
applying the parameters as set forth in the claims of the present application”
(App. Br. 4). Appellants contend that “the present process is not obvious
over Redepenning alone or combination with the remaining references”
(App. Br. 6).
We are not persuaded. Given the teaching by Lopez Lacomba that
chitosan will adhere to metal surfaces (FF 1-3) and the teaching by
Redepenning that chitosan can be deposited using current onto cathodic
surfaces (FF 4-5), we conclude that the formation of a chitosan coating on a
metal article would have been the obvious and expected result, not an
unexpected result.
Appellants contend that it “was by no means predictable for a person
skilled in the art at the time the application was filed that it is possible to
apply a cathodic polarization process for depositing chitosan onto a metallic
surface” (App. Br. 8). Appellants contend that this “is clear simply by
Appeal 2011-009322
Application 10/918,743

11
looking at the structure of chitosan. A person skilled in the art would expect
that chitosan would hardly adhere to a metallic surface due to its rather
unpolar nature” (App. Br. 8).
Again, we remain unpersuaded by these arguments because they are
flatly contradicted by the evidence of record, where Lopez Lacomba teaches
that chitosan will adhere to a metal surface (FF 1-3), which sets the
expectation of the person of ordinary skill. In addition, Redepenning shows
that a cathodic polarization process will deposit chitosan onto the cathode
surface, demonstrating this would have been expected (FF 4-5).
Appellants rely upon the Sewing Declaration7 to demonstrate
unexpected results. Sewing teaches that “the dip coating process provides
only coatings of low quality compared to the coatings obtained by cathodical
polarization” (Sewing Dec. 8).
We are not persuaded by the Sewing Declaration. The comparison of
Sewing was not made with the closest prior art of Redepenning, where
cathodic deposition of chitosan onto metallic surfaces was performed, but
rather with Lopez Lacomba, who did not use cathodic deposition. See In re
Baxter Travenol Labs., 952 F.2d 388, 392 (Fed. Cir. 1991) (“[W]hen
unexpected results are used as evidence of nonobviousness, the results must
be shown to be unexpected compared with the closest prior art.”).
The Examiner has found, and Appellants do not rebut, that
the findings touted as unexpected, namely that the electrical
resistance of a coating applied by electrochemical deposition
is higher than that applied by dip coating with the same
molecules and that a coating applied by dip coating to a

7 Declaration of Andreas Sewing, filed October 1, 2009.
Appeal 2011-009322
Application 10/918,743

12
metallic surface is less adhesive to this surface than one
applied via electrochemical deposition with the same
molecule onto a metallic surface, were known in the prior art
at the time of the invention.

“Expected beneficial results are evidence of obviousness of a claimed
invention. Just as unexpected beneficial results are evidence of
unobviousness.” In re Skoner, 517 F.2d 947, 950 (CCPA 1975).
Claim 21
In interpreting claim 21, this claim differs from claim 15 in lacking
the word “solely”, instead stating that “the chitosan coating is directly
present on the metal” (Claim 21). Claim 21 also differs from claim 15 in
directly requiring that “biologically active components are added to the
chitosan-containing solution” (Claim 21).
As discussed above, Lopez Lacomba teaches adhering chitosan to
metal surfaces (FF 1-3) and Redepenning teaches deposition of a composite
coating of hydroxyapatite and chitosan onto a metal using an electrical
current (FF 4). Redepenning always teaches that the chitosan is co-
deposited with brushite in a composite coating, either by precoating the
metal with brushite (FF 5) or when the chitosan and calcium phosphate are
deposited together (FF 6-7). Redepenning teaches that the calcium
phosphate is biologically active, noting that “hydroxyapatite is known to be
biocompatible and has been shown to enhance both interfacial shear strength
and bone contact when utilized with implant materials such as titanium or
other conductive metal alloys” (Redepenning 1 ¶ 0003; FF 8). Redepenning
teaches a range of current densities which overlaps the claimed range of 0.1
to 20 mA/cm2 (FF 4).
Appeal 2011-009322
Application 10/918,743

13
We therefore find that Redepenning reasonably renders obvious the
method of claim 21, since Redepenning prepares a chitosan coated metallic
article by cathodically polarizing the metallic article in an acidic chitosan-
containing solution (FF 4-7) where the chitosan is, at least partially, directly
present on the metal (FF 9). Redepenning incorporates biologically active
calcium phosphate (FF 8) and the current density of Redepenning overlaps
that of claim 21. Peterson, 315 F.3d at 1329.
Appellants contend that “it was by no means predictable at the time of
filing that 1) chitosan molecules can be deposited by electrochemical means
on a metallic surface, 2) the process parameters recited in the claims would
lead to successful coating, and 3) chitosan is able to form an impermeable
coating directly on the metallic surface” (App. Br. 12).
We are not persuaded. As an initial matter, Redepenning teaches that
chitosan molecules can be deposited by electrochemical means onto a
metallic surface using overlapping process parameters (FF 4, 9) and
Redepenning teaches a coating with minimal defects (FF 9). To the extent
that Appellants are arguing that the coating of Redepenning would not be
“impermeable”, that is an inherent property of the coating of Redepenning
and Appellants have provided no evidence to demonstrate that the coating of
Redepenning would not have been inherent. Best, 562 F.2d at 1254.
Appellants argue that under Redepenning’s conditions “it is not
possible that a chitosan layer directly forms on the metallic article” (App.
Br. 13).
We are not persuaded. First, claim 21 does not require that the entire
layer of the metal be composed of chitosan, only that there is chitosan
Appeal 2011-009322
Application 10/918,743

14
directly coating the metal, which is inherently met by Redepenning’s
teaching that the hydroxyapatite layer contains defects filled in by chitosan
(FF 9). In fact, Appellants acknowledged that the “chitosan layer does not
form a separate, distinct layer but rather fills the surface voids or defects
present in the calcium phosphate layer” (App. Br. 14). This filling in
reasonably satisfies the requirements of claim 21. Second, Appellants
simply argue, without evidence, that a current higher than 20 mA/cm2 would
destroy the chitosan layer. See In re Pearson, 494 F.2d 1399, 1405 (CCPA
1974) (“Attorney's argument in a brief cannot take the place of evidence.”)
Conclusion of Law
The evidence of record supports the Examiner’s conclusion that
Lopez Lacomba, Redepenning, Worch, and Geibler render claim 15 obvious.
The evidence of record supports the Examiner’s conclusion that
Lopez Lacomba, Redepenning, Worch, and Geibler render claim 21 obvious.
B. 35 U.S.C. § 103(a) over Lopez Lacomba, Redepenning, Worch,
Buirge, and Akiyama
Having already determined that Redepenning alone renders
independent claim 21 obvious, we do not separately address this rejection
which further adds Buirge and Akiyama. We consider these references
cumulative to the teachings of Redepenning. We affirm this rejection for the
reasons already given.
SUMMARY
In summary, we affirm the rejection of claim 15 under 35 U.S.C. §
103(a) as obvious over Lopez Lacomba, Redepenning, Worch, and Geibler.
Appeal 2011-009322
Application 10/918,743

15
Pursuant to 37 C.F.R. § 41.37(c)(1), we also affirm the rejection of claims 4,
8, 14, 16-19, 26, and 33 as these claims were not argued separately.
We affirm the rejection of claim 21 under 35 U.S.C. § 103(a) as
obvious over Lopez Lacomba, Redepenning, Worch, and Geibler. Pursuant
to 37 C.F.R. § 41.37(c)(1), we also affirm the rejection of claims 22 and 27-
31 as these claims were not argued separately.
We affirm the rejection of claim 21 under 35 U.S.C. § 103(a) as
obvious over Lopez Lacomba, Redepenning, Worch, Buirge and Akiyama.
Pursuant to 37 C.F.R. § 41.37(c)(1), we also affirm the rejection of claims
22 and 27-31 as these claims were not argued separately.

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED

lp