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Biomedical subjects

Andreas Lendlein

Publications and source records attributed to Andreas Lendlein.

6 recordsLinked to original sources

Poly(ether imide) membranes modified with poly(ethylene imine) as potential carriers for epidermal substitutes.

Poly(ether imide) (PEI) membranes were modified with a linear low-molecular weight (PETIM_0.6) and a branched high-molecular weight poly(ethylene imine) (PETIM_60). The membrane surfaces became more hydrophilic and the zeta potentials were shifted from negative to positive zeta values after immobilisation of both PETIM. These measurements also indicated the presence of a swollen surface layer in the case of PETIM_60, while a regular structuring of the surface was observed with scanning force microscopy for PETIM_0.6. A human keratinocyte cell line HaCaT was cultured on the different membranes. It was found that HaCaT cell growth was stimulated by PETIM_0.6. Cells reached earlier confluence on this substratum, while their growth was inhibited on a PEI membrane modified with PETIM_60, which makes PEI membranes modified with PETIM_0.6 a promising material for in vitro culture of epidermal transplants.

Adult↗

Biocompatibility testing of novel multifunctional polymeric biomaterials for tissue engineering applications in head and neck surgery: an overview.

Biomaterial research and tissue engineering are rapidly growing scientific fields that need an interdisciplinary approach where clinicians should be included from the onset. Biocompatibility testing in vitro and in vivo comprise the agarose-overlay test, the MTT test, direct cell seeding tests and the chorioallantoic membrane test for angiogenic effects, among others. Molecular biology techniques such as real-time polymerase chain reaction and microarray technology facilitate the investigation of tissue integration into biomaterials on a cellular and molecular level. The physicochemical characterization of biomaterials is conducted using such methods as X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Excellent biocompatibility and biofunctionality were demonstrated for a series of recently developed multifunctional biodegradable, polymeric biomaterials both in vitro and in vivo. Novel, multifunctional polymeric biomaterials offer a highly specific adjustment to the physiological, anatomical and surgical requirements and can thereby facilitate new therapeutic options in head and neck surgery.

Absorbable Implants↗

Light-induced shape-memory polymers.

Materials are said to show a shape-memory effect if they can be deformed and fixed into a temporary shape, and recover their original, permanent shape only on exposure to an external stimulus. Shape-memory polymers have received increasing attention because of their scientific and technological significance. In principle, a thermally induced shape-memory effect can be activated by an increase in temperature (also obtained by heating on exposure to an electrical current or light illumination). Several papers have described light-induced changes in the shape of polymers and gels, such as contraction, bending or volume changes. Here we report that polymers containing cinnamic groups can be deformed and fixed into pre-determined shapes--such as (but not exclusively) elongated films and tubes, arches or spirals--by ultraviolet light illumination. These new shapes are stable for long time periods, even when heated to 50 degrees C, and they can recover their original shape at ambient temperatures when exposed to ultraviolet light of a different wavelength. The ability of polymers to form different pre-determined temporary shapes and subsequently recover their original shape at ambient temperatures by remote light activation could lead to a variety of potential medical and other applications.

Journal Article↗

Biodegradable, elastic shape-memory polymers for potential biomedical applications.

The introduction of biodegradable implant materials as well as minimally invasive surgical procedures in medicine has substantially improved health care within the past few decades. This report describes a group of degradable thermoplastic polymers that are able to change their shape after an increase in temperature. Their shape-memory capability enables bulky implants to be placed in the body through small incisions or to perform complex mechanical deformations automatically. A smart degradable suture was created to illustrate the potential of these shape-memory thermoplastics in biomedical applications.

Animals↗