Biomedical polymers controlled drug release

Preparation of poly(8-caprolactone) (PCL), a biodegradable polymer that finds applications in the biomedical field for prostheses, bandages, or controlled drug release matrix for active substances, was successfully accomplished by heating the monomer in the presence of nontoxic, biologically acceptable lanthanide halides (SmBrj, SmCl3, YbBrj) as initiators in a scientific microwave unit (Scheme 3.5). PCL with a Af of 14,100 g/mol was obtained after heating at 200 °C for 45 min in the absence of solvent. 

PEAs are a branch of relatively new polymers. Research in the biomedical field is just starting to investigate possibilities in areas such as controlled drug release systems [215], hydrogels [216], tissue engineering [217,218], and other uses like adhesives and smart materials, together with the main families of functionalized PEAs that have been developed to date [214]. 

Polymer nanofibers for biomedical and biotechnological applications such as tissue engineering, controlled drug release, wound dressing, medical implants, nanocomposites for dental restoration, molecular separation, biosensors, and preservation of bioactive agents were reviewed. ... 

As already reflected by the number of review papers, the interest in biomedical applications of polyphosphazenes continues to grow. The biodegradable polymer NP(NHC6H4C02H-4)i.8(NHC6H4C02H-4)o.2 n has been prepared and fully characterized. The carboxylato groups can react with Ca -ions to form crosslinks and to convert the water-soluble polymer to a hydrogel. Controlled drug release experiments have been carried out for chitosan en-... 

Developments in the u.se of biodegradable polymers in biomedical and surgical applications are reviewed. Applications discussed include tissue engineering, bone fracture fixation devices, resorbable sutures, vascular grafts, temporary barriers for the prevention of postoperative adhesion, artificial skin and systems for controlled drug release. 92 refs. 

A survey is made of developments in the use of polymers in biomedical applications, including vascular prostheses, orthopaedic implants, membranes for haemodialysis and haemofiltration, intraocular and contact lenses, controlled drug release, artificial skin and artificial pancreases. 19 refs. 

Finally, new scientific advancements have opened the door for the use of polymers in biomedical applications, which may provide future benefits to Navy personnel. This is a relatively new field, but skin grafts, biocompatible coatings, and controlled drug release applications are already being tested. 

Chemical structure of monomers and intermediates was confirmed by FT-IR and FT-NMR. Molecular weight distribution of polymers was assessed by GPC and intrinsic viscosity. The thermal property was examined by differential scanning calorimetry. The hydrolytic stability of the polymers was studied under in vitro conditions. With controlled drug delivery as one of the biomedical applications in mind, release studies of 5-fluorouracil and methotrexate from two of these polymers were also conducted. 

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