Metal-organic frameworks: Drug delivery applications and future prospects.

Background and purpose: Metal-organic frameworks (MOFs) have gained incredible consideration in the biomedical field due to their flexible structural configuration, tunable pore size and tailorable surface modification. These inherent characteristics of MOFs portray numerous merits as potential drug carriers, depicting improved drug loading, site-specific drug delivery, biocompatibility, biodegradability, etc. Review approach: The current review article sheds light on the synthesis and use of MOFs in drug delivery applications. In the beginning, a brief overview of the key components and efficient fabrication techniques for MOF synthesis, along with its characterization methods, have been presented. The MOFs-based formulations have been critically discussed. The application of the design of experiments (DoE) approach to optimize MOFs has been elucidated. The MOFs-based formulations, especially the application of stimuli-responsive MOFs for site-specific drug delivery, have been deciphered. Along with drug release kinetic models, several administration methods for MOFs have also been enunciated. Subsequently, MOFs as future potential drug carriers have been elaborated. Key results and conclusion: Recently, MOFs have emerged as versatile drug delivery carriers possessing customization potential and meeting the needs of spatio-temporal drug delivery. Researchers have devised several environment-friendly approaches for MOF construction and surface modification. Owing to stimuli-responsive potential, MOFs have demonstrated their prominent therapeutic efficacy via several routes of administration. The numerous benefits of MOFs would certainly open up a new vista for its novel drug delivery applications.

Off-pump coronary artery bypass in severe left ventricular dysfunction.

The outcome of multivessel off-pump coronary artery bypass grafting in cases of severe left ventricular dysfunction was studied in 58 consecutive patients with ejection fraction < or =35% who were followed up for a median of 15 months. Patients with ejection fractions < or =25% (group 1) had the largest left ventricular dimensions preoperatively, with gradual increases during follow-up; those with ejection fractions of 26%-35% (group 2) had smaller preoperative ventricular dimensions, with left ventricular regression postoperatively. There was more improvement in ejection fraction in group 2 than group 1 (33% vs. 10%). Mitral regurgitation improved from moderate to mild in group 2; whereas in group 1, mild mitral regurgitation progressed to moderate or severe during follow-up. Ejection fraction was a predictor of more frequent use of intraaortic balloon pumping, longer duration of inotropic use, a higher mean pulmonary artery-to-systemic arterial pressure ratio, and increased postoperative drainage.

Valvuloplasty in the treatment of rheumatic tricuspid disease.

Organic involvement of the tricuspid valve is uncommon. Valve repair is preferred over replacement as it results in a low gradient across the valve and obviates the risk of prosthesis-related complications. From October 2002 to October 2004, 37 patients who required tricuspid valve repair for organic involvement were included in this study. They were divided into 2 groups depending on the surgical procedure for valve repair: 20 patients in group 1 had tricuspid commissurotomy and De Vega annuloplasty; 17 in group 2 had tricuspid commissurotomy only. There were significant reductions in peak and mean tricuspid gradients and right ventricular systolic pressure in both groups. Annular shortening was similar in both groups (median, 23% in group 1, 21% in group 2), but the ratio of the tricuspid regurgitation jet area to right atrial area was greater in group 2 (median, 0.40 in group 2, 0.19 in group 1). There was no postoperative death. We recommend supporting the tricuspid annulus with annuloplasty in patients with organic tricuspid valve disease and no dilatation of the annulus, if annular shortening is < 30%.