Management of knee osteoarthritis. Current status and future trends.

Osteoarthritis (OA) affects a large number of the population, and its incidence is showing a growing trend with the increasing life span. OA is the most prevalent joint condition worldwide, and currently, there is no functional cure for it. This review seeks to briefly overview the management of knee OA concerning standardized pharmaceutical and clinical approaches, as well as the new biotechnological horizons of OA treatment. The potential of biomaterials and state of the art of advanced therapeutic approaches, such as cell and gene therapy focused primarily on cartilage regeneration are the main subjects of this review. Biotechnol. Bioeng. 2017;114: 717-739. © 2016 Wiley Periodicals, Inc.

Recent progress in gellan gum hydrogels provided by functionalization strategies.

Gellan gum, a microbial exopolysaccharide fermentation product of Pseudomonas elodea, is a natural biomaterial that has shown promise for tissue engineering and regenerative medicine applications. Although this exopolysaccharide possesses many advantages, such as interesting physicochemical properties and non-cytotoxicity, the mechanical properties and processability of gellan gum are not totally satisfactory in different tissue engineering contexts, i.e. gellan gum hydrogels are mechanically weak and the high gelling temperature is also unfavourable. An additional critical limitation is the lack of specific attachment sites for anchorage-dependent cells. However, the multiple hydroxyl groups and the free carboxyl per repeating unit of gellan gum can be used for chemical modification and functionalization in order to optimize its physicochemical and biological properties. A number of physical modification approaches have also been employed. This review outlines the recent progress in gellan gum hydrogels and their derivatives, and identifies the new challenges in tissue engineering, provided by blending and/or chemical modification.

Synthesis and in vitro evaluation of substituted pyrimido[5,4-d]pyrimidines as a novel class of anti-Mycobacterium tuberculosis agents.

Novel pyrimido[5,4-d]pyrimidines were efficiently synthesized and evaluated for antibacterial activity against Mycobacterium tuberculosis strain H(37)Rv. This new structural class of compounds showed high activity against the bacilli. The activity depends on the substituents present in N-3 and C-8 of the pyrimido[5,4-d]pyrimidine core. Compounds having a 4-MeOC(6)H(4), a Ph or a 4-FC(6)H(4) group as the substituent on C-8 and a 4'-pyridinyl, a Ph or 2'-furyl group as the substituent on N-3 were active. The highest activity was registered for compounds having 4-FC(6)H(4) or 4-MeOC(6)H(4) as substituents in C-8 and a heteroaryl group as substituent in N-3. The new compounds showed high potency and promising antitubercular activity, as is the case of N-[8-[(4-fluorophenyl)amino]-4-iminopyrimido[5,4-d]pyrimidin-3(4H)-yl]isonicotinamide with an IC(90)=3.58 microg/mL, and should be regarded as new hits for further development as a novel class of Antimycobacterium tuberculosis agents.