Optimal 99mTc radiolabeling and uptake of glucosamine sulfate by cartilage. A potential tracer for scintigraphic detection of osteoarthritis

Transdermal co-delivery of glucosamine sulfate and diacerein for the induction of chondroprotection in experimental osteoarthritis

The aim of this work was to develop a transdermal delivery system consisting of a glucosamine sulfate-laden xanthan hydrogel containing a nanoemulsion-loaded diacerein. The system was intended to prevent cartilage degradation typical of osteoarthritis. The nanoemulsion, made of soybean oil as the oil phase; soybean lecithin, Tween 80, and poloxamer 407 as surfactants; and propylene glycol as cosurfactant, was formed within the hydrogel. The hydrodynamic diameter of the nanoemulsion globules was 81.95 ± 0.256 nm with 0.285 ± 0.036 of PDI value and the zeta potential value of the formulation was 39.33 ± 0.812 mV. CryoSEM and TEM studies revealed the uniform morphology of the vehicle. A rheological study exposed the nanoemulsion-loaded hydrogel as a thixotropic system. Satisfactory storage stability under ICH conditions was established by the zeta potential and rheological studies. Furthermore, skin biocompatibility of the hydrogel was ascertained on the basis of skin irritation study. Additionally, the diffusion of the drugs across rat skin followed a controlled non-Fickian anomalous steady mechanism. Following in vivo administration in experimental osteoarthritis, the transdermal hydrogel showed a reduction in tumor necrosis factor-alpha, C-reactive protein, high mobility group box protein, and monocyte chemoattractant protein-1. Finally, histopathological analysis of the animals showed satisfactory chondroprotection in the in vivo study. In conclusion, the developed transdermal systems showed a potential against the progression of experimental osteoarthritis.

Nondestructive Techniques to Evaluate the Characteristics and Development of Engineered Cartilage

In this review, methods for evaluating the properties of tissue engineered (TE) cartilage are described. Many of these have been developed for evaluating properties of native and osteoarthritic articular cartilage. However, with the increasing interest in engineering cartilage, specialized methods are needed for nondestructive evaluation of tissue while it is developing and after it is implanted. Such methods are needed, in part, due to the large inter- and intra-donor variability in the performance of the cellular component of the tissue, which remains a barrier to delivering reliable TE cartilage for implantation. Using conventional destructive tests, such variability makes it near-impossible to predict the timing and outcome of the tissue engineering process at the level of a specific piece of engineered tissue and also makes it difficult to assess the impact of changing tissue engineering regimens. While it is clear that the true test of engineered cartilage is its performance after it is implanted, correlation of pre and post implantation properties determined non-destructively in vitro and/or in vivo with performance should lead to predictive methods to improve quality-control and to minimize the chances of implanting inferior tissue.