Fabrication of porous collagen-stem cells-dexamethasone scaffold as a novel approach for regeneration of mandibular bone defect.

Background: Bone defects, particularly in the mandible, pose significant clinical challenges due to the limited regenerative capacity. Effective bone tissue engineering requires biomaterials that promote both osteogenesis and angiogenesis. This study developed an optimized collagen-nano hydroxyapatite scaffold loaded with dexamethasone and stem cells to enhance bone regeneration.

Different therapeutic approaches in melasma: advances and limitations.

Melasma is a chronic hyperpigmentation skin disorder that is more common in the female gender. Although melasma is a multifactorial skin disorder, however, sun-exposure and genetic predisposition are considered as the main etiologic factors in melasma occurrence. Although numerous topical and systemic therapeutic agents and also non-pharmacologic procedural treatments have been considered in melasma management, however, the commonly available therapeutic options have several limitations including the lack of sufficient clinical effectiveness, risk of relapse, and high rate of unwanted adverse drug reactions.