Yan Yuhua

Biodegradation of tricalcium phosphate ceramics by osteoclasts

SummaryBiodegradation of tricalcium phosphate (TCP) ceramics was observed through mixed culture of osteoclasts and TCP discsin vitro in this study. Osteoclasts were isolated from newborn SD rat’s marrow of long bone and cultured on TCP discs. The culture terminated at the 48th h and 96th h respectively. Under an inverted microscope, the osteoclasts imparted round or oval body with multinuclear and many thin processes. These cells were positively stained for tartrate-resistance acid phosphatase (TRAP). Scanning electron microscope showed that many resorption lacunae on TCP disc surface and their diameters were smaller than 20 μm. Osteoclasts were located in the lacunae. At the 96th h, the resorption lacunae become larger and osteoclasts showed degeneration. It is suggested that osteoclasts possess ability to re-absorb TCP ceramics underin vitro culturing condition.

A new drug delivery system—Ciprofloxacine/tricalcium phosphate delivery capsule (CTDC) and itsIn Vitro drug release pattern

A new drug delivery system (DDS), ciprofloxacine/tricalcium phosphate delivery capsule (CTDC) was developed by loading a broad-spectrum antibiotic ciprofloxacine into the central cylindrical cavity of tricalcium phosphate capsule. The new system showed good biocompatibility and could degrade gradually in our preliminary studies. In vitro study showed that CTDC could maintain high-level and long-term release of ciprofloxacine and that ultrasonic irradiation within the range of physical therapy could increase the drug release amount from CTDC ( P < 0.02), and might become a new technique to achieve the control of drug release from DDS.SummaryA new drug delivery system (DDS), ciprofloxacine/tricalcium phosphate delivery capsule (CTDC) was developed by loading a broad-spectrum antibiotic ciprofloxacine into the central cylindrical cavity of tricalcium phosphate capsule. The new system showed good biocompatibility and could degrade gradually in our preliminary studies.In vitro study showed that CTDC could mantain high-level and long-term releae of ciprofloxacine and that ultrasonic irradiation within the range of physical therapy could increase the drug release amount from CTDC (P<0. 02), and might become a new technique to achieve the control of drug release from DDS.

The bacterial inhibitory ability andin vivo drug release pattern of a new drug delivery system: Ciprofloxacine/tricalcium phosphate delivery capsule

SummaryThe bacterial inhibitory ability of a new drug delivery system (DDS): Ciprofloxacine/tricalcium phosphate delivery capsule (CTDC), itsin vivo drug release pattern, and the influence of ultrasonic irradiation on its drug release were investigated. It was found that CTDC had a strong and sustained inhibitory ability to some common pathogens of bone and joint infections, such as staphylococcus aureus, escherichia coli and pseudomonas aeruginosa.In vivo drug-release study in animals demonstrated a high concentration of ciprofloxacine in the bone tissue surrounding CTDC which was placed in the greater trochanter of the rabbit and continued to release ciprofloxacine for at least 5 weeks and the blood level of ciprofloxacine was low.In vivo study also showed ultrasonic irradiation could increase the amount of ciprofloxacine released from CTDC, which may be an economical, effecient and safe new method to achieve the control of drug release from DDS.