Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect resulting in significant reductions in systemic toxicity. Nonetheless, insufficient release of encapsulated drug from liposomes has limited their clinical efficacy. Temperature-sensitive liposomes have been engineered to provide site-specific release of drug in order to overcome the problem of limited tumor drug bioavailability. Our lab has designed and developed a heat-activated thermosensitive liposome formulation of cisplatin (CDDP), known as HTLC, to provide triggered release of CDDP at solid tumors. Heat-activated delivery in vivo was achieved in murine models using a custom-built laser-based heating apparatus that provides a conformal heating pattern at the tumor site as confirmed by MR thermometry (MRT). A fiber optic temperature monitoring device was used to measure the temperature in real-time during the entire heating period with online adjustment of heat delivery by alternating the laser power. Drug delivery was optimized under magnetic resonance (MR) image guidance by co-encapsulation of an MR contrast agent (i.e., gadoteridol) along with CDDP into the thermosensitive liposomes as a means to validate the heating protocol and to assess tumor accumulation. The heating protocol consisted of a preheating period of 5 min prior to administration of HTLC and 20 min heating post-injection. This heating protocol resulted in effective release of the encapsulated agents with the highest MR signal change observed in the heated tumor in comparison to the unheated tumor and muscle. This study demonstrated the successful application of the laser-based heating apparatus for preclinical thermosensitive liposome development and the importance of MR-guided validation of the heating protocol for optimization of drug delivery.
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http://dx.doi.org/10.3791/53055 | DOI Listing |
J Interv Card Electrophysiol
December 2024
Arrhythmia Unit, Cardiology Department,, Hospital Universitario Doctor Balmis, Alicante, Spain.
Background: The aim of cavotricuspid isthmus (CTI)-dependent flutter ablation is the bidirectional conduction block of the CTI. Very-high-power short-duration (vHPSD) radiofrequency ablation aims to minimize conductive heating and increase resistive heating to create shallower but wider lesions in a very short time, while reducing the risk of collateral tissue damage. Experimental studies have shown that it produces effective transmural lesions with an equal or better safety profile compared to conventional parameters.
View Article and Find Full Text PDFFood Chem
December 2024
Institute for Egg Science and Technology, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, Sichuan, China. Electronic address:
Egg white protein's functional properties and digestibility can be significantly affected by processing methods. In this study, a novel combined ultrasound-heating (UH) pretreatment protocol was developed, where liquid egg white was subjected to ultrasonic treatment (0.4 W/mL, 10 min) followed by mild heating (72 °C, 10 min) prior to drying processes.
View Article and Find Full Text PDFJ Exp Biol
December 2024
Department of Biology, University of Central Oklahoma, Edmond, OK 73034, USA.
Organisms may simultaneously face thermal, desiccation and nutritional stress under climate change. Understanding the effects arising from the interactions among these stressors is relevant for predicting organisms' responses to climate change and for developing effective conservation strategies. Using both dynamic and static protocols, we assessed for the first time how sublethal desiccation exposure (at 16.
View Article and Find Full Text PDFRSC Adv
December 2024
Bioorganic Laboratory, Department of Chemistry, University of Delhi Delhi-110007 India
A synthesis of a small library of fluorescent 1,4-dihydropyridine nucleoside analogues has been successfully carried out under solvent-free conditions a one-pot three-component Hantzsch condensation reaction. The process involved a Ba(NO) catalyzed solvent-free reaction between 3',5'-di--acetyl-5-formyl-2'-deoxyuridine, differently substituted β-keto ester and ammonium acetate under microwave irradiation. This facile methodology yielded the desired products with very high yields (86-96%) under solvent-free reaction conditions in a short reaction time, which was followed by a simple workup.
View Article and Find Full Text PDFBMC Musculoskelet Disord
December 2024
Department of Orthopaedics, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing, 100191, China.
Background: A warning system to avoid potential nerve root thermal injury caused by automatic spine robot is essential. However, there is a lack of basic research to support the development of such warning system. The aims of this study are to confirm the feasibility of continuous intraoperative neuromonitoring (CIONM) in spinal nerve root monitoring and study the exposure time of spinal nerve root thermal injury at different temperature in a porcine model.
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