Liposomes — microscopic phospholipid bubbles with a bilayered membrane structure — have received a lot of attention during the past 30 years as pharmaceutical carriers of great potential. More recently, many new developments have been seen in the area of liposomal drugs — from clinically approved products to new experimental applications, with gene delivery and cancer therapy still being the principal areas of interest. For further successful development of this field, promising trends must be identified and exploited, albeit with a clear understanding of the limitations of these approaches.

Recent advances with liposomes as pharmaceutical carriers.

Hydrogels for tissue engineering.

Foreign body reaction to biomaterials.

http://www.tara.tcd.ie/bitstream/handle/2262/54960/Biomaterials%20and%20scaffolds%20for%20tissue%20engineering.pdf;sequence=1

Biomaterials & scaffolds for tissue engineering

American College of Cardiology Clinical Expert Consensus Document on Standards for Acquisition, Measurement and Reporting of Intravascular Ultrasound Studies (IVUS). A report of the American College of Cardiology Task Force on Clinical Expert Consensus Documents.

▪ Abstract All materials intended for application in humans as biomaterials, medical devices, or prostheses undergo tissue responses when implanted into living tissue. This review first describes fundamental aspects of tissue responses to materials, which are commonly described as the tissue response continuum. These actions involve fundamental aspects of tissue responses including injury, inflammatory and wound healing responses, foreign body reactions, and fibrous encapsulation of the biomaterial, medical device, or prosthesis. The second part of this review describes the in vivo evaluation of tissue responses to biomaterials, medical devices, and prostheses to determine intended performance characteristics and safety or biocompatibility considerations. While fundamental aspects of tissue responses to materials are important from research and development perspectives, the in vivo evaluation of tissue responses to these materials is important for performance, safety, and regulatory reasons.

Biological Responses to Materials

Host response to tissue engineered devices

The implantation of artificial organs, medical devices, or biomaterials results in injury and initiation of the inflammatory response. This inflammatory response to implants has as its components acute inflammation, chronic inflammation, foreign body reaction with granulation tissue, and macrophage and foreign body giant cell interactions. The form and topography of the surface of the artificial organ, medical device, prosthesis, or biomaterial can determine the composition of the foreign body reaction. The normal foreign body reaction consists of macrophages and foreign body giant cells at the surface of the implant with subjacent fibroblastic proliferation and collagen deposition, and capillary formation. Macrophages play a pivotal role in the response of tissue to implants. An hypothesis on the role of complement activation and complement-mediated cellular adhesion to implant surfaces has been presented. Macrophage adhesion and subsequent activation leading to cell-mediator and cell-cell communication is described.

James M. Anderson

Papers

Foreign body reaction to biomaterials.

Biological Responses to Materials

Host response to tissue engineered devices

Inflammatory response to implants.

Biomaterial biocompatibility and the macrophage.