Mesenchymal Stem Cells: From Regeneration to Drug Delivery Systems.

Targeting drug delivery has been a focus of researchers in recent years for cancer and other diseases. Many approaches such as liposomes, exosomes, nanoparticles (magnetic), encapsulation etc. have been developed and investigated for their clinical applications. But disadvantages linked to these therapies limit them to be used in clinical settings. Cell based drug delivery systems has emerged as an alternative for these therapies. Among cell types, mesenchymal stem cells (MSCs) proved to a potential cell type for research due to its many characteristics including low immunogenicity, chemotaxis and homing to tumor sites which are considered mandatory for drug delivery. This chapter focuses on the challenges and opportunities in using MSCs as therapeutic carrier of drugs in different ailments.

Gastric Residual Volume Assessment by Gastric Ultrasound in Fasting Obese Patients: A Comparative Study.

BACKGROUND: Gastric ultrasound is an emerging tool for preoperative evaluation of gastric content and volume. OBJECTIVES: To assess gastric residual volume in normal-weight and obese patients scheduled for elective surgery. METHODS: This prospective observational study was conducted on 100 patients assigned to two groups of 50 patients each. The obese group included patients with body mass index (BMI) of 30 - 40 and American Society of Anesthesiologists (ASA) grade II and those with BMI > 40 and ASA III without other comorbidities; the normal-weight group included patients with normal BMI and ASA I. Gastric volume was predicted in each group using sonographic measurement of antral cross-sectional area (CSA) in semi-sitting and right lateral positions (RLP); the two groups were compared to assess the risk of aspiration for each group preoperatively. RESULTS: Despite intergroup differences in antral CSA, the sonographically predicted gastric volume was < 1.5 mL/kg in both groups in both positions. Both groups were at a low risk for aspiration, and 98% of the patients showed grade 0 or 1 in antrum assessments, corresponding to an empty antrum and minimal fluid only in the RLP, respectively. Only 2% of the patients in both groups showed a distended antrum in both positions. CONCLUSIONS: Despite the differences in CSA between obese and normal-weight participants in both positions (obese > normal-weight), both groups showed a low predicted gastric residual volume < 1.5 mL/kg and were at low risk for aspiration, provided that fasting was initiated at least 8 hours before elective surgery.