Antibacterial implants

Septicin antibacterial implant for the treatment of chronic bone infections have been developed [21-24]. The multidisciplinary concept of polymeric implants has expanded to include research on the chemistry and characterization of polymers, experimental and theoretical polymer degradation and drug release, toxicology and metabolism, and research in specific fields of applications such as cancer, proteins and hormones delivery, infectious diseases, and brain disorders. This chapter concentrates on the chemistry and characterization of polyanhydrides with a brief description on recent applications of polyanhydrides. 

Nablo BJ, Rothrock AR, Schoenfisch MH. Nitric oxide-releasing sol-gels as antibacterial coatings for orthopedic implants. Biomaterials 2005, 26, 917-924. 

Gollwitzer H, Ibrahim K, Meyer H et al. (2003) Antibacterial poly(D,L-lactic acid) coating of medical implants using a biodegradable drug delivery technology. J Antimicrob Chemother 51 585-591... 

The immobilisation of antibacterial coatings onto conductive materials such as stainless steel or carbon fibre used in orthopaedic implants was investigated by two methods. The formation of thin films by electrodeposition of polypyrrole doped with polyanions able to complex silver ions, and their characterisation by SEM, FTIR and microbiological testing is described. The alternative method, involving chemical grafting of a thin film of a quatemaiy ammonium polymer using a surface initiator, is also discussed. 2 refs. 

EM s chemical structure consists of a 14-membered macrocyclic lactone ring (erythronolide) connected to a deoxyamino sugar (desosamine) and a deoxy sugar (cladinose) as shown in Fig. 5. We synthesized about 250 EM derivatives and examined their GMS and antibacterial activities [19, 20]. GMS activity was tested by intravenous injection of the test compounds to fasted conscious dogs with permanently implanted force transducers in the stomach, and antibacterial activity was estimated as minimum inhibitory concentration (MIC) by agar dilution method. The EM derivatives shown in Fig. 5 exhibited higher GMS activities with less antibacterial activities compared with those of EM (Table I). 

Pharmacokinetic data show that the progestogen component (levonorg-estrel, norethisterone) of combined oral contraceptives is not affected by ampicillin, clarithromycin, doxycycline, metronidazole, moxi-floxacin, or tetracycline. There is no reason to expect that the contraceptive efficacy of the various progestogen-only methods (tablets, implants, injections, lUDs) would be affected by antibacterials that alter gut flora and do not induce liver enzymes. 

The final consideration to be addressed in this chapter on the choice of a polymer fortrsein medical devices is cost. Biomedical polymers can range from inexpensive (PVC, polyethylene) to extremely expensive (e.g., polymers with peptide components). A disposable catheter intended for minutes or hotus use in the body will not jrrstily an expensive polymer. On the other hand, a device implanted with the intent of a lifetime of acceptable performance might rrse an expensive polymeric component if long-term performance benefit can be demonstrated. Also, a higher priced polymer might be justified based on reduced complications. For example, as catheter-related bloodstream infections can add over 56000 to a hospital stay, a more expensive antibacterial catheter should be justified. ... 

The total biomedical PEG literature includes thousands of papers and hundreds of applications. Some of the applications, in addition to those mentioned above, include dmg delivery depots, cell encapsulants, lubricious surfaces, mucoadhesive dmg carriers, coatings for miaofluidic devices, antibacterial coatings, nonthrombogenic coatings, control of cell fusion, applications in ophthalmic implants, and separation membranes. 

Surface modification of a fiber can be accomplished by chemical treatment, graft copolymerization, ion implantation, or plasma treatment. Surface modification usually targets improvements in antistatic properties, moisture regain, dyeing, printing, adhesion, abrasion, antibacterial properties, and so forth. 

Conductive polymer nanocomposites may also be used in different electrical applications such as the electrodes of batteries or display devices. Linseed oil-based poly(urethane amide)/nanostuctured poly(l-naphthylamine) nanocomposites can be used as antistatic and anticorrosive protective coating materials. Castor oil modified polyurethane/ nanohydroxyapatite nanocomposites have the potential for use in biomedical implants and tissue engineering. Mesua ferrea and sunflower seed oil-based HBPU/silver nanocomposites have been found suitable for use as antibacterial catheters, although more thorough work remains to be done in this field. ° Sunflower oil modified HBPU/silver nanocomposites also have considerable potential as heterogeneous catalysts for the reduction of nitro-compounds to amino compounds. Castor oil-based polyurethane/ epoxy/clay nanocomposites can be used as lubricants to reduce friction and wear. HBPU of castor oil and MWCNT nanocomposites possesses good shape memory properties and therefore could be used in smart materials. ... 

As discussed earlier, the incidence of postoperative infection remains a major issue, often with dire conseqnences following implantation. Titanium implants are widely used clinically bnt also suffer from this issue. Therefore, surfaces with antibacterial coatings are extranely desirable. Research has demonstrated that incorporation of silver nanoparticles into titanium nanotubes enable such effects. Zhao et al. [51] showed adequate activity against planktonic bacteria within several days and preventing their subsequent growth for np to 30 days. 

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