This paper reviews biodegradable synthetic polymers focusing on their potential in tissue engineering applications. The major classes of polymers are briefly discussed with regard to synthesis, properties and biodegradability, and known degradation modes and products are indicated based on studies reported in the literature. A vast majority of biodegradable polymers studied belongs to the polyester family, which includes polyglycolides and polylactides. Some disadvantages of these polymers in tissue engineering applications are their poor biocompatibility, release of acidic degradation products, poor processability and loss of mechanical properties very early during degradation. Other degradable polymers such as polyorthoesters, polyanhydrides, polyphosphazenes, and polyurethanes are also discussed and their advantages and disadvantages summarised. With advancements in tissue engineering it has become necessary to develop polymers that meet more demanding requirements. Recent work has focused on developing injectable polymer compositions based on poly (propylene fumarate) and poly (anhydrides) to meet these requirements in orthopaedic tissue engineering. Polyurethanes have received recent attention for development of degradable polymers because of their great potential in tailoring polymer structure to achieve mechanical properties and biodegradability to suit a variety of applications.

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Biodegradable synthetic polymers for tissue engineering

Elastomeric biomaterials for tissue engineering

A surgical stapling apparatus includes a jaw assembly including a pair of jaw members and a surgical buttress positioned adjacent a tissue contacting surface of at least one of the pair of jaw members. The surgical buttress includes a hemostatic agent and is configured to release the hemostatic agent therefrom upon actuation of the surgical stapling apparatus to approximate the pair of jaw members and exert a pressure on the surgical buttress.

Buttress film with hemostatic action for surgical stapling apparatus

Compounds are provided which can form bioabsorbable compositions useful as adhesives or sealants for medical/surgical applications.

Bioabsorbable surgical composition

Vegetable-oil-based polymers as future polymeric biomaterials.

Polyurethanes, having extensive structure/property diversity, are one of the most bio- and blood-compatible materials known today. These materials played a major role in the development of many medical devices ranging from catheters to total artificial heart. Properties such as durability, elasticity, elastomer-like character, fatigue resistance, compliance, and acceptance or tolerance in the body during the healing, became often associated with polyurethanes. Furthermore, propensity for bulk and surface modification via hydrophilic/hydrophobic balance or by attachments of biologically active species such as anticoagulants or biorecognizable groups are possible via chemical groups typical for polyurethane structure. These modifications are designed to mediate and enhance the acceptance and healing of the device or implant. Many innovative processing technologies are used to fabricate functional devices, feeling and often behaving like natural tissue. The hydrolytically unstable polyester polyurethanes were replaced by more resistant but oxidation-sensitive polyether polyols based polyurethanes and their clones containing silicone and other modifying polymeric intermediates. Chronic in vivo instability, however, observed on prolonged implantation, became a major roadblock for many applications. Presently, utilization of more oxidation resistant polycarbonate polyols as soft segments, in combination with antioxidants such as Vitamin E, offer materials which can endure in the body for several years. The applications cover cardiovascular devices, artificial organs, tissue replacement and augmentation, performance enhancing coatings and many others. In situ polymerized, cross-linked systems could extend this biodurability even further. The future will expand this field by revisiting chemically-controlled biodegradation, in combination with a mini-version of RIM technology and minimally invasive surgical procedures, to form, in vivo, a scaffold, by delivery of reacting materials to the specific site in the body and polymerizing the mass in situ. This scaffold will provide anchor for tissue regeneration via cell attachment, proliferation, control of inflammation, and healing.

Biomedical Applications of Polyurethanes: A Review of Past Promises, Present Realities, and a Vibrant Future:

The present invention relates generally to the utilization of in situ polymers or copolymers to form a porous microcellular scaffold for the delivery, attachment, housing, protection, multiplication and growth of encapsulated cells. More particularly, the present invention relates to cells delivered using such a scaffold to augment, repair or replace in vivo diseased, damaged or otherwise compromised tissues or organs of a living body.

In vivo tissue engineering with biodegradable polymers

The present invention relates generally to surgical implants intended for the augmentation, repair, and restoration of soft tissue (e.g. gingiva or cartilage), hard tissue (e.g. bone), and the like. More particularly, the present invention relates to the in vivo anchoring of cast implants by stent-like anchors made of a shape memory alloy and/or polymers which are desirably covered with a textile sleeve of a specific porosity.

Surgical implant system for restoration and repair of body function

A loss of function of an organ often represents a life-threatening situation. Transplantations are successful, but "replacement" availability, its compatibility with the host, and subsequent healing often pose serious questions. Tissue engineering, where a carefully prepared scaffold is populated, in vitro, by cells to form an artificial organ, addresses some of the problems mentioned above. Trauma associated with the implant introduction to the host often complicates the process.The novel concept of in vivo tissue engineering which is designed to mediate the healing and tissue regeneration process by providing an in vitro formed porous, microcellular scaffold is proposed. The scaffold (part or entire organ) is then populated by cells either spontaneously (the surrounding cells will spread and populate to inhabit the scaffold) or by cellular augmentation (encapsulated cells are delivered to this in status nascendi scaffold). Minimally traumatic arthroscopic surgery combined with a unique polymer delivery ...

Ivanka J. Zdrahala

Papers

Biomedical Applications of Polyurethanes: A Review of Past Promises, Present Realities, and a Vibrant Future:

In vivo tissue engineering with biodegradable polymers

Surgical implant system for restoration and repair of body function

In vivo tissue engineering : Part I. Concept genesis and guidelines for its realization