DoE-Assisted Development of a Novel Glycosaminoglycan-Based Injectable Formulation for Viscosupplementation

EPR Viscometric Measurements Using a 13C-Labeled Triarylmethyl Radical in Protein-based Biotherapeutics and Human Synovial Fluids

The viscosity measurements are of clinical significance for evaluation of the potential pathological conditions of biological lubricants such as synovial fluids of joints, and for formulation and characterization of peptide- and protein-based biotherapeutics. Due to inherent potential therapeutic activity, protein drugs have proven to be one of the most efficient therapeutic agents in treatment of several life-threatening disorders, such as diabetes and autoimmune diseases. However, home-use applications for treating chronic inflammatory diseases, such as diabetes and rheumatoid arthritis, necessitate the development of high-concentration insulin and monoclonal antibodies formulations for patient self-administration. High protein concentrations can affect viscosity of the corresponding drug solutions complicating their manufacture and administration. The measurements of the viscosity of new insulin analogs and monoclonal antibodies solutions under development is of practical importance to avoid unwanted highly viscous, and therefore, painful for injection drug formulations. Recently, we have demonstrated capability of the electron paramagnetic resonance (EPR) viscometry using viscosity-sensitive 13C-labeled trityl spin probe (13C1-dFT) to report the viscosity of human blood, and interstitial fluids measured in various organs in mice ex-vivo and in anesthetized mice, in vivo. In the present work, we demonstrate utility of the EPR viscometry using 13C1-dFT to measure microviscosity of commercial insulin samples, antibodies solution, and human synovial fluids using small microliter volume samples (5-50 μL). This viscometry analysis approach provides useful tool to control formulations and administration of new biopharmaceuticals, and for evaluation of the state of synovial fluids of importance for clinical applications.

Experimental Therapeutics for the Treatment of Osteoarthritis

Osteoarthritis (OA) therapy remains a large challenge since no causative treatment options are so far available. Despite some main pathways contributing to OA are identified its pathogenesis is still rudimentary understood. A plethora of therapeutically promising agents are currently tested in experimental OA research to find an opportunity to reverse OA-associated joint damage and prevent its progression. Hence, this review aims to summarize novelly emerging experimental approaches for OA. Due to the diversity of strategies shown only main aspects could be summarized here including herbal medicines, nanoparticular compounds, growth factors, hormones, antibody-, cell- and extracellular vesicle (EV)-based approaches, optimized tools for joint viscosupplementation, genetic regulators such as si- or miRNAs and promising combinations. An abundant multitude of compounds obtained from plants, environmental, autologous or synthetic sources have been identified with anabolic, anti-inflammatory, -catabolic and anti-apoptotic properties. Some ubiquitous signaling pathways such as wingless and Integration site-1 (Wnt), Sirtuin, Toll-like receptor (TLR), mammalian target of rapamycin (mTOR), Nuclear Factor (NF)-κB and complement are involved in OA and addressed by them. Hyaluronan (HA) provided benefit in OA since many decades, and novel HA formulations have been developed now with higher HA content and long-term stability achieved by cross-linking suitable to be combined with other agents such as components from herbals or chemokines to attract regenerative cells. pH- or inflammation-sensitive nanoparticular compounds could serve as versatile slow-release systems of active compounds, for example, miRNAs. Some light has been brought into the intimate regulatory network of small RNAs in the pathogenesis of OA which might be a novel avenue for OA therapy in future. Attraction of autologous regenerative cells by chemokines and exosome-based treatment strategies could also innovate OA therapy.