Surface Modification of Porous Polyethylene Implants with an Albumin-Based Nanocarrier-Release System

Background: Porous polyethylene (PPE) implants are used for the reconstruction of tissue defects but have a risk of rejection in case of insufficient ingrowth into the host tissue. Various growth factors can promote implant ingrowth, yet a long-term gradient is a prerequisite for the mediation of these effects. As modification of the implant surface with nanocarriers may facilitate a long-term gradient by sustained factor release, implants modified with crosslinked albumin nanocarriers were evaluated in vivo. Methods: Nanocarriers from murine serum albumin (MSA) were prepared by an inverse miniemulsion technique encapsulating either a low- or high-molar mass fluorescent cargo. PPE implants were subsequently coated with these nanocarriers. In control cohorts, the implant was coated with the homologue non-encapsulated cargo substance by dip coating. Implants were consequently analyzed in vivo using repetitive fluorescence microscopy utilizing the dorsal skinfold chamber in mice for ten days post implantation. Results: Implant-modification with MSA nanocarriers significantly prolonged the presence of the encapsulated small molecules while macromolecules were detectable during the investigated timeframe regardless of the form of application. Conclusions: Surface modification of PPE implants with MSA nanocarriers results in the alternation of release kinetics especially when small molecular substances are used and therefore allows a prolonged factor release for the promotion of implant integration.

Outcome of Auricular Reconstruction with Porous Polyethylene Frameworks: Our 10 Years of Experience with 113 Children and Adults

This study evaluates the surgical outcome and patient benefit after auricular reconstruction with porous polyethylene frameworks and temporoparietal fascia flaps in both children and adults. A total of 161 patients who had undergone auricular reconstruction between 2003 and 2014 by doctors in our department were asked to answer both a validated health-related quality-of-life questionnaire (Glasgow Benefit Inventory or Glasgow Children's Benefit Inventory) and a questionnaire reporting satisfaction, complaints, and complications with the reconstructed pinna. Furthermore, postoperative surgical complications were recorded. A total of 113 patients (89 individuals older than 14 and 24 children under the age of 14) returned the questionnaires. About 80% of the patients were satisfied with the results of their auricular reconstruction. The main complaints concerned scars and the shape. Patients' quality of life was correlated with their postoperative aesthetic satisfaction. Thus, framework extrusion was the principal factor affecting patients' satisfaction, whereas treatable postoperative complications did not interfere with the overall quality of life. Interestingly, children indicated greater benefit from auricular reconstruction than older patients. With regard to the patient's feeling of being physically healthy after auricular reconstruction, partial pinna reconstruction and reconstruction without simultaneous hearing restoration should be very carefully considered. Auricular reconstruction using a porous polyethylene framework significantly increases the patients' health-related quality of life and leads to significant patient satisfaction, especially in the case of younger patients.