# Nanostructured surfaces with improved hemocompatibility

> **NIH NIH R21** · COLORADO STATE UNIVERSITY · 2023 · $28,291

## Abstract

PROJECT SUMMARY/ABSTRACT:
Blood-contacting medical devices, such as stents and heart valves, are common treatments in modern
healthcare. Every year, approximately 1 million and 90,000 stent and prosthetic heart valve procedures are
performed in the US, respectively. However, the use of these devices is associated with substantial risk of
thrombosis, and the rate of failure due to clot formation can be as high as 6%. When whole blood plasma comes
in contact with a foreign body (e.g., an implant), it leads to four main events capable of inducing a thrombogenic
response in vivo: protein adsorption, platelet adhesion/activation, leukocyte recruitment, and further activation of
complement and coagulation. Within seconds to minutes, key blood plasma proteins are adsorbed and undergo
conformational changes on the surface. This layer of adsorbed protein will allow subsequent adhesion and
activation of platelets, which promotes the formation of the fibrin clot, as well as the recruitment of leukocytes.
The platelets then initiate an inflammatory immune response and promote a complex cascade of events resulting
in thrombosis and/or fibrous encapsulation of the implant. Due to this complex foreign body response,
hemocompatibility has been a significant issue for blood-contacting medical devices. To address this challenge,
the development of novel biomaterials that can appropriately interact with blood and prevent thrombosis is vital
for the success of many implantable devices. In this work, we propose to prevent thrombosis on implants by
combining the promising properties of two biopolymers with nanoscale features on titania to develop a novel
blood-compatible surface. Biopolymers are good candidates for these applications, because of their compatibility
with the human body, biodegradability, processability and, in some cases, inherent antifouling and
antithrombogenic properties. Our preliminary results indicate that carboxymethylation of kappa-carrageenan with
monochloroacetic acid to form carboxymethyl-kappa-carrageenan (CMKC) improves the antithrombogenic
properties. CMKC is chemically similar to heparin and prevents thrombosis through multiple mechanisms.
However, CMKC is derived from algae, a renewable and low-cost source, while heparin is obtained from animal
tissues. Moreover, CMKC does not cause the side effects that heparin presents, such as bleeding effects. Our
group also has recently used of tanfloc (TA), a condensed tannin polymer as a biomaterial, and we have
demonstrated its promising cytocompatibility, antioxidant activity, antimicrobial, and antifouling properties.
Previous studies done by our group showed that the modification of titanium surfaces with TA and heparin
decreased the blood protein adsorption/activation, and platelet adhesion and activation. This work aims to
combine these promising properties of both biopolymers (CMKC and TA) to develop novel surfaces on titanium
that can prevent thrombosis.

## Key facts

- **NIH application ID:** 10686166
- **Project number:** 5R21EB033511-02
- **Recipient organization:** COLORADO STATE UNIVERSITY
- **Principal Investigator:** Matthew Kipper
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $28,291
- **Award type:** 5
- **Project period:** 2022-08-18 → 2024-01-16

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10686166

## Citation

> US National Institutes of Health, RePORTER application 10686166, Nanostructured surfaces with improved hemocompatibility (5R21EB033511-02). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10686166. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*