Biodegradable nanocomposites with enhance mechanical properties for soft tissue

Abstract

The present invention is directed to a novel poly(diol citrates)-based nanocomposite materials created using completely biodegradable and biocompatible polymers that may be used in tissue engineering. More specifically, the specification describes methods and compositions for making and using nanocomposites comprised of citric acid copolymers and polymers including but not limited to poly(L-lactic acid) (PLLA) and poly(lactic-co-glycolic acid) (PLGA).

Description

[0001] The present application claims the benefit of priority of U.S. Provisional Application No. 60 / 721,687 which was filed Sep. 28, 2005. The entire text of the aforementioned application is incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention is generally directed to a substrate used for tissue engineering. The substrate is a biodegradable elastomeric polymer. Methods and compositions for testing and using the same are disclosed. BACKGROUND [0003] The need for biodegradable polymers in emerging technologies such as tissue engineering, drug delivery, and gene therapy has been fueling a quest for novel biodegradable polymers [13-16]. In particular, biodegradable polymers with elastomeric properties have recently received attention for their potential use in the engineering of soft tissues such as blood vessel, heart valves, cartilage, tendon, and bladder, which exhibit elastic properties. Due to their long history of use in clinical applications, pol...

AI Technical Summary

Benefits of technology

[0015] Also contemplated herein is a method of producing engineered tissue, comprising providing a biodegradable composition of the present invention as a scaffold for the growth of cells and culturing cells of said tissue on the scaffold. In preferred methods, the polymer is composite of a poly 1,8-octanediol-co-citric acid, or a derivative thereof, or a poly 1,10-decanediol-co-citric acid or derivative thereof in combination with a biodegradable polymer such as PGLA or PLLA. In specific embodiments, the cells are selected from the group consisting of connective tissue cells, organ cells, muscle cells, nerve cells, and any combination thereof. In more specific embodiments, the cells are selected from the group consisting of tenocytes, fibroblasts, ligament cells, endothelial cells, lung cells, epithelial cells, smooth muscle cells, cardiac muscle cells, skeletal muscle cells, islet cells, nerve cells, hepatocytes, kidney cells, bladder cells, urothelial cells, chondrocytes, and bone-forming cells. In other preferred embodiments, the tissue engineering method comprises growing the cells on the scaffold in a bioreactor.

Problems solved by technology

Although this method has been used for industrial applications, there have been no reports involving the use of biocompatible, biodegradable nanoparticles to strengthen matrices intended for in vivo use.

However, most of these approaches introduce inorganic and non-biodegradable components into the polymer composite.

A non-degradable second phase may interfere with the body's natural remodeling mechanisms as the continuous presence of a foreign material may induce long-term inflammatory responses.

Furthermore, the resulting composite does not exhibit the elasticity and flexibility that is important for soft tissue engineering.

However, Chun et al, Melican et al, and Ma et al do not disclose composites having mechanical properties approaching those of natural soft tissue.

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