A review of nanoparticle photosensitizer drug delivery uptake systems for photodynamic treatment of lung cancer.

Lung cancer is a leading cause of cancer related deaths worldwide and so current research is focused on trying to improve treatment modalities, such as photodynamic therapy (PDT). PDT has 3 fundamental factors, namely a photosensitizer (PS) drug, light and oxygen. When a PS drug is administered to a patient, it can either passively or actively accumulate within a tumour site and once exposed to a specific wavelength of light, it is stimulated to produce reactive oxygen species (ROS), resulting in tumour destruction. However, the efficacy of ROS generation for tumour destruction is highly dependent on the accumulation of the PS in tumour cells. Thus PS selective/targeted uptake and delivery in tumour cells is a crucial factor in PDT cancer drug absorption studies. Generally, within non-targeted drug delivery mechanisms, only small amounts of PS is able to passively accumulates in tumour sites due to the enhanced permeability and retention (EPR) effect and the remainder distributes into healthy tissues, causing side effects. Thus to improve the efficacy of PDT, research is currently focused on the development of specific receptor based photosynthetic nanocarrier drugs, which promotes the active uptake and absorption of PS drugs in tumour sites only, avoiding unwanted side effects. The aim of this review is to focus on current non-targeted passive versus specifically active targeted PS nanoparticle drug delivery systems, that have been investigated for the PDT treatment of lung cancer and so to deduce its efficacy and recent advancements.

Natural options for management of melasma, a review.

A blemish free, even-toned skin is universally associated with healthy skin. This reasoning makes people desire to have a flawless skin. Melanin is a naturally occurring pigment in humans. This pigment is responsible for skin, hair, and eye color, therefore determines our race and phenotypic appearance. On darker skin types, it is common that melanin production processes malfunctions. These malfunctions often lead to overproduction and secretion of melanin. As a result, unwanted pigmentary problems such melasma occur. Due to unknown etiology and its recurrence in nature, melasma is challenging to treat. The current available melasma treatment options often produce undesired side effects and suboptimum results. First-line topical treatments usually involve hydroquinone or topical steroids. Apart from the irritant reactions, this treatment mode is not suitable for all skin types. Skin care specialists are in search of an effective long-term cosmetics and cosmeceuticals to address hypermelanosis problems. Understanding of naturally occurring depigmenting agents provides an opportunity for more effective ways to manage melasma in all skin types. This review considers the benefits of naturally occurring ingredients which could help address skin pigmentation problems and broaden the choice for skin-lightening treatments.