Fundamental laser-skin interaction effects were studied using a CO2 laser. The photodamaged areas obtained from laser interaction were recorded via couple charge device video camera and analyzed via ImageJ software. Photodamage induced by CO2 laser is due to photothermal effects, which involve burning and vaporizing mechanisms to ablate the epidermis layer. The burning area literally expands and penetrates deep into the dermis layer, subsequently causing collagen coagulation. This fundamental study shows in detail the effect of CO2 laser interaction with skin. The CO2 attributed severe burning, producing deep coagulation, and induced strength to treated skin.

Wound healing is a complex matrix and overlapping process. In order to accelerate the healing process and minimize bacterial infection, lightbased therapy was applied to stimulate bioreaction to improve healing. The aim of this paper is to review the effects induced by light source (laser and incoherent light like LED) on different biological targets. The light based therapy techniques were categorized according to the wavelength, energy density, type of irradiance and activity of tissues in the healing process. Out of 80 cases, 77% were animal studies, 5% were human studies and 18% were cell studies. Around 75% of light based therapy has an advantage on tissue interaction and 25% has no effect or inhibition on the healing process. The appropriate dose appears to be between 1 and 5 J cm −2. At shorter wavelength, photobiostimulation would be effective with a high frequently administrated lowenergy dose. On the other hand, for longer wavelength it is the reverse, i.e., more effective with a low frequent treated schedule and a highenergy dose.

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Customized cinnamon-based nanostructures are of great demand for broad arrays of nanomedical, biomedical and photocatalytic purposes. Conventional methods for cinnamon nanomaterials production with desirable optical absorption and emission properties are still limited. This communication elucidates the role of growth media (liquid ethanol and methanol) in controlling the optical qualities of cinnamon nanoparticles (CNPs). Such CNPs of varied morphologies were prepared using pulsed laser ablation in liquid (PLAL) technique (a simple, an inexpensive, and an eco-friendly approach). In the PLAL process, clean cinnamon sticks (as target material purchased from supermarket) were ablated via Q-switched Nd:YAG laser pulse of wavelength 532 nm operated at optimum fluence of 5.73 J/cm2. As-synthesized CNPs were characterized at room temperature using ultraviolet-visible (UV-Vis) absorption and photoluminescence (PL) emission spectroscopy. Uniformly dispersed high purity colloidal CNPs with narrow size distribution was achieved. The UV-Vis absorption and the PL spectra of CNPs revealed prominent peaks. These observed distinctive absorption and emission traits of studied CNPs were ascribed to the effects of oxygen deficiency, quantum confinement, crystal defects and existence of cinnamaldehyde compounds. In short, the nucleation and growth of CNPs was significantly sensitive to the chemical character of liquid suspension that provided a favorable thermodynamic condition via entropy driven free energy minimization. It was demonstrated that the structural, morphological, physical, optical properties of such CNPs can be tailored by intuitively selecting the liquid growth media. This disclosure affirmed that the present systematic approach can constitute a basis for the large-scale production of CNPs effective for widespread applications.

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