Osteoarthritis, which typically arises from aging, traumatic injury, or obesity, is the most common form of arthritis, which usually leads to malfunction of the joints and requires medical interventions due to the poor self-healing capacity of articular cartilage. However, currently used medical treatment modalities have reported, at least in part, disappointing and frustrating results for patients with osteoarthritis. Recent progress in the design and fabrication of tissue-engineered microscale/nanoscale platforms, which arises from the convergence of stem cell research and nanotechnology methods, has shown promising results in the administration of new and efficient options for treating osteochondral lesions. This paper presents an overview of the recent advances in osteochondral tissue engineering resulting from the application of micro- and nanotechnology approaches in the structure of biomaterials, including biological and microscale/nanoscale topographical cues, microspheres, nanoparticles, nanofibers, and nanotubes.

Background: Protein pharmaceuticals routinely display a series of intrinsic physicochemical instability problems during their production and administration that can unfavorably affect their therapeutic effectiveness. Glycoengineering is one of the most desirable techniques to improve the attributes of therapeutic proteins. One aspect of glycoengineering is the rational manipulation of the peptide backbone to introduce new N-glycosylation consensus sequences (Asn-X-Ser/Thr, where X is any amino acid except proline). Methods: In this work, the amino acid sequence of human chorionic gonadotropin (hCG) was analyzed to identify the suitable positions in order to create new N-glycosylation sites. This survey led to the detection of 46 potential N-glycosylation sites. The N-glycosylation probability of the all potential positions was measured with the NetNGlyc 1.0 server. After theoretical reviews and the removal of unsuitable positions, the five acceptable ones were selected for more analyses. Then, three-dimensional (3D) structures of the selected analogs were generated and evaluated by SPDBV software. The molecular stability and flexibility profile of five designed analogs were examined using molecular dynamics (MD) simulations. Results: Finally, three analogs with one additional N-glycosylation site (V68T, V79N and R67N) were proposed as the qualified analogs that could be glycosylated at the new sites. Conclusion: According to the results of this study, further experimental investigations could be guided on the three analogs. Therefore, our computational strategy can be a valuable method due to the reduction in the number of the expensive, tiresome and time-consuming experimental studies of hCG analogs.