Development of Multifunctional Commercial Pure Titanium-Polyethylene Glycol Drug-Eluting Substrates with Enhanced Optical and Antithrombotic Properties.

PURPOSE: Development of multifunctional advanced stent implants (metal/polymer composite)-drug-eluting stents with superior material and optical properties is still a challenge. In this research work, multifunctional metal-polymer composite drug-eluting substrates (DES) for stent application were developed by using commercially pure titanium (cpTi) and polyethylene glycol (PEG). METHODS: Surface modifications on titanium substrates were carried out by sodium hydroxide under various concentrations; 5M (6 and 24 h) and 10M (6 and 24 h). It induces a nanoporous structure which facilitates the larger area for encapsulation of the drug, Aspirin (ASA) via intermolecular forces followed by polymer coating of PEG (MW-20,000) by physical adsorption process, which is structured as layer-by-layer gathering. RESULTS: The developed cpTi-PEG DES were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), optical energy bandgap, static contact angle measurement, antithrombotic and drug release studies. The development of sodium titanate oxide prompted surface nano-features revealed by SEM and XRD. Moreover, FTIR confirms the presence of ASA and PEG functional groups over the cpTi surface. Drug release studies fitted with Ritger-Peppas kinetic model (≤ 60%), which indicates the super case II transport mechanisms (n > 1). Further UV-visible absorbance spectrum was quantified by the Tauc plot, which shows the broadening of the energy bandgap (Eg). In addition, the shrink in blood clots was more around the Tib2/ASA/PEG.Please confirm the inserted city name in affiliations [1,2] are correct and amend if necessary.Yes, city name "Rourkela" is correct. CONCLUSION: Developed cpTi-PEG DES has improved optical properties and prevent thrombus formation which suggesting it a potential substrate to overcome prime clinical challenges.

An Experimental and Numerical Study on Nodular Gel Phantom during Cryotherapy.

BACKGROUND: Cryogen spray cooling is an effective method to treat nodular basal cell carcinoma. OBJECTIVE: To study the effect of spraying distance (z = 27 mm, 18 mm and 9 mm) on a nodular gel phantom and to validate the numerical model. MATERIALS AND METHODS: Liquid nitrogen is sprayed on agarose gel phantom using 0.8 mm nozzle diameter. A two-dimensional Pennes equation with phase change is solved on the axisymmetric non-orthogonal grid. RESULTS: The lethal front is obtained at 4 mm from the gel surface, irrespective of spraying distance and the same is validated with numerical results. The maximum necrotic volume and lethal front achieved by -50C and -25C isotherms seem to have a lower dependence on the spraying distance as opposed to those corresponding to the 0C isotherm. In contrast, the initiation of these parameters is highly dependent on the nozzle to gel height. CONCLUSION: The numerical study presents good agreement with experimental data. The decrease in spraying distance leads to higher rate of maximum ablation volume during freezing, but final ablation volume remained approximately similar.

A Novel Adjuvant-Solution Layer Strategy for Improving the Efficacy of Cryosurgery.

BACKGROUND: During cryosurgery, studies reported earlier suggest increased destruction inside the tumour due to adjuvants or the prevention of damage to neighbouring healthy tissue through different methods. OBJECTIVE: This study advocates a novel strategy that increases the freezing inside agarose gel phantoms by addition of glycine and limits the freezing to the desired location using a perfluorohexane layer during cryosurgery. MATERIALS AND METHODS: Cryosurgery of glycine containing gels is carried out with and without perfluorohexane layer and the thermal history is measured using K-type thermocouples connected to a data acquisition system. RESULTS: The presence of glycine causes increased freezing during cryosurgery with an ice ball depth of 16 mm, while with a perfluorohexane layer at this gel interface, this depth is 13 mm, indicating the ability of this layer to limit freezing. CONCLUSION: It can be concluded that glycine addition results in substantial temperature decrease and perfluorohexane layer insulates the glycine gel effectively during cryosurgical cooling.

Microwave-assisted synthesis of porous chitosan-modified montmorillonite-hydroxyapatite composite scaffolds.

In this study, a porous chitosan-organically modified montmorillonite-hydroxyapatite (CS-OM-HA) composite scaffold was developed by combining microwave irradiation and gas foaming method. Hydroxyapatite (HA) particles of size ∼ 65 nm were synthesized and characterized by X-ray diffraction (XRD) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The prepared composite scaffolds were characterized using ATR-FTIR, XRD, mercury intrusion porosimeter (MIP) and scanning electron microscopy (SEM) studies. The synergistic effect of HA and OM on the mechanical and in vitro biological properties (swelling, degradation, protein adsorption and bioactivity) of the composite scaffolds were evaluated. Swelling, degradation, mechanical property, bioactivity and protein adsorption studies of CS-OM-HA composite scaffolds have shown desirable results in comparison with the pure CS and CS-OM composite scaffolds. CS-OM-HA composite scaffolds were also found to be non-cytotoxic to MG 63 osteoblast cell lines. From the study, it can be concluded that the novel CS-OM-HA composite scaffold with improved mechanical and in vitro biological properties has wide potential in non-load bearing bone tissue engineering applications.

Genipin-Crosslinked Gelatin-Based Emulgels: an Insight into the Thermal, Mechanical, and Electrical Studies.

The present study discusses about the preparation and characterization (thermal, mechanical, and electrical) of the genipin-crosslinked gelatin emulgels. Emulgels have gained importance in recent years due to their improved stability than emulsions and ability to control the drug release. Mustard oil was used as the representative oil. A decrease in the enthalpy and entropy of the formulations was observed with the increase in the oil fraction. The mechanical studies suggested formation of softer emulgels as the oil fraction was increased. As the proportion of the oil fraction was increased in the emulgels, there was a corresponding increase in the impedance. The drug release properties from the emulgels were also studied. Ciprofloxacin was used as the model antimicrobial drug. The drug release was higher from the emulgels whose electrical conductivity was higher.

Primary endotracheal neurogenic tumors.

Benign tumors in the tracheobronchial tree are rare. We report two cases of primary endotracheal neurogenic tumors in patients who presented insidiously. Both patients did not manifest other clinical features of neurofibromatosis (Von Recklinghausen's disease). A single procedure using rigid bronchoscopy and neodymium: yttrium-aluminum-garnet laser resection resulted in excellent resolution of airway patency with good follow-up results in both cases.