Functionalized chitosan nanoparticles for cutaneous delivery of a skin whitening agent: an approach to clinically augment the therapeutic efficacy for melasma treatment.

The increase in the production of melanin level inside the skin prompts a patient-inconvenient skin color disorder namely; melasma. This arouses the need to develop efficacious treatment modalities, among which are topical nano-delivery systems. This study aimed to formulate functionalized chitosan nanoparticles (CSNPs) in gel form for enhanced topical delivery of alpha-arbutin as a skin whitening agent to treat melasma. Ionic gelation method was employed to prepare α-arbutin-CSNPs utilizing a 24 full factorial design followed by In vitro, Ex vivo and clinical evaluation of the nano-dispersions and their gel forms. Results revealed that the obtained CSNPs were in the nanometer range with positive zeta potential, high entrapment efficiency, good stability characteristics and exhibited sustained release of α-arbutin over 24 h. Ex vivo deposition of CSNPs proved their superiority in accumulating the drug in deep skin layers with no transdermal delivery. DSC and FTIR studies revealed the successful amorphization of α-arbutin into the nanoparticulate system with no interaction between the drug and the carrier system. The comparative split-face clinical study revealed that α-arbutin loaded CSNPs hydrogels showed better therapeutic efficacy compared to the free drug hydrogel in melasma patients, as displayed by the decrease in: modified melasma area and severity index (mMASI) scores, epidermal melanin particle size surface area (MPSA) and the number of epidermal monoclonal mouse anti-melanoma antigen recognized by T cells-1 (MART-1) positive cells which proved that the aforementioned system is a promising modality for melasma treatment.

Carboxytherapy Versus Skin Microneedling in Treatment of Atrophic Postacne Scars: A Comparative Clinical, Histopathological, and Histometrical Study.

BACKGROUND: Acne scarring has been a challenge to treat. Microneedling gained popularity in treatment of such scars. Meanwhile, carboxytherapy (CXT) is considered a novel treatment modality for acne scars. OBJECTIVE: To evaluate efficacy of CXT versus microneedling in treatment of acne scars. METHODS AND MATERIALS: Thirty-two patients with atrophic acne scars received 6 sessions of microneedling and CXT on right and left sides of face, respectively. Clinical evaluation with histopathological and computerized morphometric analysis was performed at 2 months after treatment. RESULTS: After either microneedling or CXT, there was significant decrease of total acne scars and its 3 types separately (icepicks, boxcar, and rolling) (p ≤ .001). Comparing both sides of face, there was no significant difference regarding grading response and reduction percentage of total scars and its types (p > .05). Histopathologically, there was an improvement of character and organization of collagen and elastic fibers in addition to significant increase in epidermal thickness on both sides of face, with no significant difference between them (p > .05). CONCLUSION: Both CXT and microneedling are equally effective, tolerable, safe, and noninvasive treatment modalities of atrophic acne scars. Similar histopathological changes were observed after both modalities, helping in better understanding their action.