Repair of dural defects with electrospun bacterial cellulose membranes in a rabbit experimental model

To evaluate the advantages and mechanisms involved in repairing rabbit dural defect with a novel electrospun bacterial cellulose (EBC) membrane, a series of experiments were carried out in vitro and in vivo. Compared with common bacterial cellulose (BC) membrane, a more dispersed and regular fiber structure and a better porosity and water holding capacity were found in the EBC membrane, which also had superior degradability. However, the biomechanical properties were slightly decreased. The results demonstrated that BC and EBC membranes had little effect on proliferation and apoptosis of mouse fibroblast cells. There were no complications such as infection, cerebrospinal fluid leakage, epilepsy and brain swelling after BC and EBC membrane repairs in rabbit models. Using real-time quantitative polymerase chain reaction (RT-qPCR) and western blot, the early inflammatory reactions in the EBC group were shown to be lower than in the BC group, and were close to the autologous dura mater group. Histological observations and western blot revealed more collagen fibers evenly distributed on the outer side of EBC membranes than in the BC and unpatched groups, and fewer brain tissue adhesions and epidural scars were found in the EBC group. Compared with common BC membrane, the EBC membrane had better biophysical properties and biocompatibility. It is expected to be a suitable alternative material for the repair of damaged dura mater.

Frontier of therapeutic antibody discovery: The challenges and how to face them

Therapeutic monoclonal antibodies have become an important class of modern medicines. The established technologies for therapeutic antibody discovery such as humanization of mouse antibodies, phage display of human antibody libraries and transgenic animals harboring human IgG genes have been practiced successfully so far, and many incremental improvements are being made constantly. These methodologies are responsible for currently marketed therapeutic antibodies and for the biopharma industry pipeline which are concentrated on only a few dozen targets. A key challenge for wider application of biotherapeutic approaches is the paucity of truly validated targets for biotherapeutic intervention. The efforts to expand the target space include taking the pathway approach to study the disease correlation. Since many new targets are multi-spanning and multimeric membrane proteins there is a need to develop more effective methods to generate antibodies against these difficult targets. The pharmaceutical properties of therapeutic antibodies are an active area for study concentrating on biophysical characteristics such as thermal stability and aggregation propensity. The immunogenicity of biotherapeutics in humans is a very complex issue and there are no truly predictive animal models to rely on. The in silico and T-cell response approaches identify the potential for immunogenicity; however, one needs contingency plans for emergence of anti-product antibody response for clinical trials.