Biocompatibility and erosion behavior of implants made of triglycerides and blends with cholesterol and phospholipids

Implants as Sustained Release Delivery Devices for Vaccine Antigens

“…Tripalmitinbased implants have also been developed and employed for the delivery of protein drugs such as insulin (Appel et al 2006 ), interleukins , lysozyme, and neurotropic factor (Koennings et al 2007 ). Also, lipid implants prepared from cholesterol alone or mixtures of cholesterol and phospholipids, as well as implants made of triglycerides and blends of cholesterol and phospholipids (Guse et al 2006 ) have been explored for the delivery of model antigens such as ovalbumin (OVA) and BSA (Khan et al 1991(Khan et al , 1993Myschik et al 2008a , b , d ), showing that the sustained release of antigen with or without the inclusion of an adjuvant is possible. The shift from polymeric matrix material to lipids can be explained by the fact that lipids are naturally occurring substances and therefore, a foreign body response is less likely to be raised by the immune system.…”

“…The shift from polymeric matrix material to lipids can be explained by the fact that lipids are naturally occurring substances and therefore, a foreign body response is less likely to be raised by the immune system. However, even for triglyceride-cholesterol implants blended with phospholipids, an infl ammatory reaction was reported when phospholipid content in the implants was increased to higher concentrations (Guse et al 2006 ).…”

“…However, sometimes the magnifi cation that can be achieved using optical microscopy may not be suffi cient, meaning that further analysis involving the use of scanning electron microscopy is necessary. Here surface properties such as roughness, porosity, or pore formation during release can be investigated in more depth (Guse et al 2006 ;Myschik et al 2008a ). Pore formation can also be analyzed after drying of the implants using mercury porosimetry where the application of a high pressure forces a non-wetting liquid, e.g., mercury, into the implant matrix.…”

“…Cardamone et al observed some local foreign body responses to their implant, however, the authors concluded that this response may be benefi cial for vaccination (Cardamone et al 1997 ). Guse et al observed foreign body reactions to implants made of phospholipids and glyceroltripalmitate (Guse et al 2006 ).…”

Polymer Delivery of Hydroxycamptothecin against C6 Glioma

“…Hydroxycamptothecin polymer discs (12 mg, final weight) were prepared by compression molding. For this, 12.0 -13.0 mg of hydroxycamptothecin polymer powder was prepared using a stainless steel mold (internal diameter, 3.0 mm) under pressure at 250 N as described by Leong et al [8] [9].…”