Remote loading of curcumin-in-modified β-cyclodextrins into liposomes using a transmembrane pH gradient

Curcumin (CRM) is a natural polyphenol with antioxidative, anti-inflammatory, and anticancer therapeutic properties. However, CRM therapeutic potential is limited by low water solubility and bioavailability. Intraliposomal remote loading describes the retention of drugs in liposome cores in response to transmembrane pH gradient. The current study describes for the first time the remote loading of CRM into liposomes using secondary (E-βCD) and tertiary (D-βCD) amino-modified β-cyclodextrins (βCDs) as carriers and solubilizers. βCDs were chemically modified to prepare the ionizable weak base functional group followed by forming a guest-host complex of CRM in the modified βCDs hydrophobic cavities via a solvent evaporation encapsulation technique. These complexes were then actively loaded into preformed liposomes, composed of DPPC/cholesterol (65/35 molar ratio) via pH gradient. The formation of CRM-βCDs inclusion complexes was characterized using UV-Vis spectroscopy, thermal analysis, and NMR spectroscopy. The complex stoichiometric ratio was determined to be 1 : 1 of CRM-βCDs based on Job''s plot which was also confirmed by the modified Benesi–Hildebrand equation with increasing probability of forming the 1 : 2 ratio of CRM-βCDs. The apparent formation constants (K_f) of 51.6, 100.9 and 55.4 mM⁻² were determined for CRM-βCD, CRM-E-βCD, and CRM-D-βCD complexes, respectively. Liposome size, charge and polydispersity index indicate the presence of a homogeneous population before and after active loading. The encapsulation efficiencies of CRM-βCD complexes into pH gradient preformed liposomes were 16.5, 51.1, and 41.7 for CRM-βCD, CRM-E-βCD, and CRM-D-βCD, respectively, showing more than 5 fold increase compared to normal liposomes. The current study provides a novel remote loading approach utilizing chemically modified cyclodextrins to incorporate hydrophobic drugs into liposomes.

The current study provides a novel remote loading approach utilizing chemically modified cyclodextrins to incorporate hydrophobic drugs into liposomes.     

Quercetin-gold nanorods incorporated into nanofibers: development,optimization and cytotoxicity

Herein, a polymeric nanofiber scaffold loaded with Quercetin (Quer)–gold nanorods (GNR) was developed and characterized. Several parameters related to loading Quer into GNR, incorporating the GNR-Quer into polymeric solutions, and fabricating the nanofibers by electrospinning were optimized. GNR-Quer loaded into a polymeric mixture of poly(lactic-co-glycolic acid) (PLGA) (21%) and poloxamer 407 (23%) has produced intact GNR-Quer-nanofibers with enhanced physical and mechanical properties. GNR-Quer-nanofibers demonstrated a slow pattern of Quer release over time compared to nanofibers free of GNR-Quer. Dynamic mechanical thermal analysis (DMTA) revealed enhanced uniformity and homogeneity of the GNR-Quer-nanofibers. GNR-Quer-nanofibers demonstrated a high ability to retain water upon incubation in phosphate buffer saline (PBS) for 24 h compared to nanofibers free of GNR-Quer. A cellular toxicity study indicated that the average cellular viability of human dermal fibroblasts was 76% after 24 h of exposure to the nanofibers containing a low concentration of GNR-Quer.

Incorporating GNR-Quer into a mixture of 21% PLGA LMWT and 23% poloxamer 407 produced smooth, intact and uniform electrospun nanofibers with enhanced mechanical properties and hydration potential.     

Exceptional association of hypocomplementemic urticarial vasculitis syndrome (HUVS) and symptomatic pulmonary histoplasmosis: a case-based literature review

Clinical Rheumatology - Hypocomplementemic urticarial vasculitis syndrome (HUVS) is a rare type III hypersensitivity disorder characterized by urticarial vasculitis and prolonged...     

Comparison between metabolic-associated fatty liver disease and nonalcoholic fatty liver disease: From nomenclature to clinical outcomes

As a result of the obesity epidemic, Nonalcoholic fatty liver disease(NAFLD) and its complications have increased among millions of people. Consequently, a group of experts recommended changing the term NAFLD to an inclusive terminology more reflective of the underlying pathogenesis; metabolic-associated fatty liver disease(MAFLD). This new term of MAFLD has its own disease epidemiology and clinical outcomes prompting efforts in studying its differences from NAFLD.This article discusses the rati...     

COVID-19 in liver transplant patients: Impact and considerations

The coronavirus disease 2019 pandemic has significantly impacted liver transplantation worldwide, leading to major effects on the transplant process,including the pretransplant, perioperative, and post-transplant periods. It is believed that patients with chronic liver disease, especially those with cirrhosis,have a higher risk of complications from coronavirus disease 2019 infection compared to the general population. However, evaluation of coronavirus disease 2019 effects on liver transplant p...     

Liver transplantation amidst the COVID-19 era: Our center’s experience

Coronavirus disease 2019 significantly impacted the liver transplant process worldwide. Consequently, it brought significant challenges and limitations to transplant policies and organ allocation forcing liver transplant centers to adjust their protocols to ensure maximum benefit and avoid harm to their patients. Our center, like many others, was obliged to adapt to the challenges. This paper provided an overview of the effects of coronavirus disease 2019 on liver transplantations and detailed our center’s experience and efforts during this unprecedented pandemic to serve as a guide for future public health crises.