In this study one of classical antibiotic compound nitrofurantoin was studied as micro and nano particles in electrochemical analysis by cyclic voltammetric technique using glassy carbon electrode in blood medium to observe the oxidative effect on the blood components. It was found oxidation – reduction current peaks of nitrofurantoin in blood medium at +1 and -0.75 V respectively. The oxidation current peak was disappeared for the nitrofurantoin nano particles in blood medium, but for micro particles is still oxidize the blood. Different concentration and scan rate were studied to observation the electrochemical behavior of nitrofurantoin nano particles in blood medium which has good analysis.

Hydroxyapatite (HAp) – polycaprolactone (PCL) composite has found enhanced interest as scaffold material for bone tissue engineering application. The HAp phase is bioactive and provide the favorable environment for cell adhesion, proliferation, differentiation and cell conduction whereas the biodegradable PCL provide the required flexibility, mouldability and resorbability. Nanoparticles of HAp has been synthesized by precipitation method from Ca(NO3)2.4H2O and H3PO4 as precursors of Ca and P using tetrahydrofuran (THF) as the medium. The powder prepared was characterized for phase purity, functional group, particle size, surface area and morphology in comparison with the powder prepared using deionised water as the medium. By following the similar procedure of precipitation, nanoHAp was prepared in the PCL matrix with HAp to PCL ratio of 80:20 by wt % and HAp-PCL composite powder was filtered, dried at <50°C and characterized. The synthesized HAp and HAp-PCL composite show nano sized primary particles having X-ray pure hydroxyapatite phase. The HAp-PCL composite having homogeneous distribution of nanoHAp particles in PCL matrix could be a potential scaffold material for tissue engineering applications.

The main advantage of optoacoustic imaging (OAI) is the capability to detect diseases at their early stages of growth. The efficiency of this technique has been demonstrated by preliminary studies with real biological tissues and small animals. The definitive goal of in-vivo OAI is to provide maps of the absolute concentration of chromophores with the help of exogenous optical contrast agents. Usually, solid-state lasers are used for the generation of ultrasounds but their use in clinical environment is inconvenient due to their large sizes, high costs, and low repetition rates (a few Hz) that are not sufficient for a high resolution during image processing. However, the requirements of high repetition rates (up a few kHz) can be fulfilled by high-power diode lasers (HPDLs) combined in side-by-side arrays. In the present paper, we implement a three-wavelength optoacoustic (OA) system consisting on a small array of HPDLs and a diode laser bar (DLB) operating at 870 nm, 905 nm, and 972 nm, respectively, coupled to a 1.2-mm diameter optical fiber bundle. The combined beam illuminates different mixtures of two gold nanorods solutions with absorbance peak at ~ 860 nm and ~ 900 nm, respectively, to generate OA signals. The pulses produced to generate OA signals are alternated between the three wavelengths by a microcontroller circuit with fast switching (0.33 ms). An inverse algorithm is implemented to estimate the concentrations of the nanoparticles solutions from the amplitude of the OA signals. The results achieved with our system show good agreement between the concentrations of gold nanorods estimated from measurements and the expected values.

Hydroxyapatite (HAp) – polycaprolactone (PCL) composite has found enhanced interest as scaffold material for bone tissue engineering application. The HAp phase is bioactive and provide the favorable environment for cell adhesion, proliferation, differentiation and cell conduction whereas the biodegradable PCL provide the required flexibility, mouldability and resorbability. Nanoparticles of HAp has been synthesized by precipitation method from Ca(NO3)2.4H2O and H3PO4 as precursors of Ca and P using tetrahydrofuran (THF) as the medium. The powder prepared was characterized for phase purity, functional group, particle size, surface area and morphology in comparison with the powder prepared using deionised water as the medium. By following the similar procedure of precipitation, nanoHAp was prepared in the PCL matrix with HAp to PCL ratio of 80:20 by wt % and HAp-PCL composite powder was filtered, dried at <50°C and characterized. The synthesized HAp and HAp-PCL composite show nano sized primary particles having X-ray pure hydroxyapatite phase. The HAp-PCL composite having homogeneous distribution of nanoHAp particles in PCL matrix could be a potential scaffold material for tissue engineering applications.

In this study one of classical antibiotic compound nitrofurantoin was studied as micro and nano particles in electrochemical analysis by cyclic voltammetric technique using glassy carbon electrode in blood medium to observe the oxidative effect on the blood components. It was found oxidation – reduction current peaks of nitrofurantoin in blood medium at +1 and -0.75 V respectively. The oxidation current peak was disappeared for the nitrofurantoin nano particles in blood medium, but for micro particles is still oxidize the blood. Different concentration and scan rate were studied to observation the electrochemical behavior of nitrofurantoin nano particles in blood medium which has good analysis.

The purpose of this study was to prepare and to characterize a new formulation of injectable capsaicin loaded poly (D,L-lactic-co-glycolic acid) (PLGA) microspheres (CAP-MS). The emulsion solvent evaporation process based on O/W emulsion was applied to prepared the CAP-MS with optimization of formulation using uniform design with three factors and six levels. The optimized formulation was then evaluated in terms of size, encapsulation efficiencies, drug loading, in vitro release profile, distribution and pharmacokinetics. According to the mathematic models, the optimal prescription and preparation technology can be conducted at the concentration of PLGA of 2%, the rotation speed of 1000 rpm and the mass ratio (CAP/PLGA) 1:2. The optimized CAP-MS resulted in spherical shapes and possessed a smooth surface. Average diameter, encapsulation efficiency and drug loading were turned out to be 4.73µm, 82.82% and 27.60%, respectively. In vitro release study represented a low initial burst release of approximately 21.26% within the first 24 h followed by a prolonged release up to 12 days and the release kinetics fitted well to the Higuchi model. In vivo results demonstrated that the drug suspension released rapidly after subcutaneous injection, the accumulate drug release was more than 97% after 12 hours, while the drug loaded microspheres release pro?le showed a large initial burst effect (59%), and then released slowly, nearly 100% of capsaicin released at the end of 20 days. These results indicate the PLGA microspheres is a promising system that could be exploited as a delivery system for capsaicin with high drug loading capacity and sustained drug release.

A customized optical system composed of collimating and focusing lenses is proposed to achieve the beam focusing of high-brightness diode laser bars with high fill factor for optoacoustic applications. Through an optimized design, the beam of a 940-nm diode laser bar is first collimated and symmetrized between the fast and slow axes, and then is reduced in size into a square beam (~ 3.7 mm x 3.7 mm at 1/e2 of the peak) with intensity of ~ 3.2 kW/cm2. In an optoacoustic environment, the optical spot achieved can illuminate a small region of tissue at high intensity to achieve in-depth imaging with high resolution.

The main advantage of optoacoustic imaging (OAI) is the capability to detect diseases at their early stages of growth. The efficiency of this technique has been demonstrated by preliminary studies with real biological tissues and small animals. The definitive goal of in-vivo OAI is to provide maps of the absolute concentration of chromophores with the help of exogenous optical contrast agents. Usually, solid-state lasers are used for the generation of ultrasounds but their use in clinical environment is inconvenient due to their large sizes, high costs, and low repetition rates (a few Hz) that are not sufficient for a high resolution during image processing. However, the requirements of high repetition rates (up a few kHz) can be fulfilled by high-power diode lasers (HPDLs) combined in side-by-side arrays. In the present paper, we implement a three-wavelength optoacoustic (OA) system consisting on a small array of HPDLs and a diode laser bar (DLB) operating at 870 nm, 905 nm, and 972 nm, respectively, coupled to a 1.2-mm diameter optical fiber bundle. The combined beam illuminates different mixtures of two gold nanorods solutions with absorbance peak at ~ 860 nm and ~ 900 nm, respectively, to generate OA signals. The pulses produced to generate OA signals are alternated between the three wavelengths by a microcontroller circuit with fast switching (0.33 ms). An inverse algorithm is implemented to estimate the concentrations of the nanoparticles solutions from the amplitude of the OA signals. The results achieved with our system show good agreement between the concentrations of gold nanorods estimated from measurements and the expected values.