A case of Staphylococcus epidermidis osteomyelitis in the absence of spine hardware.

Staphylococcus epidermidis is a typically indolent pathogen that is often considered a blood culture contaminant. It is a rare and unexpected cause of osteomyelitis, especially in the absence of recent surgical intervention or orthopedic implants. We highlight a case in which a 90-year-old Caucasian male with no recent spine surgery was found to have osteomyelitis of the lumbar spine and repeat positive blood cultures for methicillin resistant Staphylococcus epidermidis (MRSE). Further investigation revealed a history of mitral valve replacement and a new diagnosis of endocarditis leading to persistent bacteremia and seeding of his lumbar vertebrae. This case demonstrates that S. epidermidis can cause vertebral osteomyelitis resulting in severe complications that are more similar to highly pathogenic bacteria. We describe the steps to diagnosing this chronic undetected infection and related comorbidities.

Silk fibroin rods for sustained delivery of breast cancer therapeutics.

A silk-protein based reservoir rod was developed for zero-order and long-term sustained drug delivery applications. Silk reservoir rod formulations were processed in three steps. First, a regenerated silk fibroin solution, rich in random-coil content was transformed into a tubular silk film with controllable dimensions, uniform film morphology and a structure rich in silk II, ß-sheet content via "film-spinning." Second, the drug powder was loaded into swollen silk tubes followed by tube end clamping. Last, clamped silk tube ends were sealed completely via dip coating. Anastrozole, an FDA approved active ingredient for the treatment of breast cancer, was used as a model drug to investigate viability of the silk reservoir rod technology for sustained drug delivery. The in vitro and in vivo pharmacokinetic data (in a female Sprague-Dawley rat model) analyzed via liquid chromatography-tandem mass spectroscopy indicated zero-order release for 91 days. Both in vitro and in vivo anastrozole release rates could be controlled simply by varying silk rod dimensions. The swelling behavior of silk films and zero-order anastrozole release kinetics indicated practically immediate film hydration and formation of a linear anastrozole concentration gradient along the silk film thickness. The dependence of anastrozole release rate on the overall silk rod dimensions was in good agreement with an essentially diffusion-controlled sustained release from a reservoir cylindrical geometry. In vivo results highlighted a strong in vitro-in vivo pharmacokinetic correlation and a desirable biocompatibility profile of silk reservoir rods. During a 6-month implantation in rats, the apparent silk molecular weight values decreased gradually, while rod dry mass and ß-sheet crystal content values remained essentially constant, providing a suitable timeframe for controlled, long-term sustained delivery applications. Overall, the silk reservoir rod may be a viable candidate for sustained delivery of breast cancer therapeutics.