ABSTRACT
Drug delivery with customized combinations of drugs, controllable drug dosage, and on-demand release kinetics is critical for personalized medicine. In this study, inspired by successive opening of layered structures and compartmentalized structures in plants, we designed a multiple compartmentalized capsular structure for controlled drug delivery. The structure was designed as a series of compartments, defined by the gradient thickness of their external walls and internal divisions. Based on the careful choice and optimization of bioinks composed of gelatin, starch, and alginate, the capsular structures were successfully manufactured by fused deposition modeling three-dimensional (3D) printing. The capsules showed fusion and firm contact between printed layers, forming complete structures without significant defects on the external walls and internal joints. Internal cavities with different volumes were achieved for different drug loading as designed. In vitro swelling demonstrated a successive dissolving and opening of external walls of different capsule compartments, allowing successive drug pulses from the capsules, resulting in the sustained release for about 410 min. The drug release was significantly prolonged compared to a single burst release from a traditional capsular design. The bioinspired design and manufacture of multiple compartmentalized capsules enable customized drug release in a controllable fashion with combinations of different drugs, drug doses, and release kinetics, and have potential for use in personalized medicine.
ABSTRACT
Objective: To investigate echocardiography characteristics and clinical significance in patients with diastolic mitral regurgitation. Methods: A total of 15 patients with diastolic mitral regurgitation were studied including 1 patient with large volume of aortic regurgitation, 6 with atrial ifbrillation (AF), 2 with atrial lfutter, 1 with II° type I atrio-ventricular block (A-V block), 1 with II° type II A-V block and 4 with III° A-V block. The characteristics of mitral regurgitation were observed, the heart rates, left ventricular size were measured and left ventricular function was detected in all patients. Results: There was 1 large volume aortic regurgitation patient with diastolic mitral regurgitation occurred in slow iflling phase with less volume, it was less than positive velocity; 1 AF patient occurred in mid and late diastolic phase with less volume, it was obviously less than positive velocity; the rest 8 patients all occurred in mid and late diastolic phase, the velocity reached or surpassed to positive velocity. All 15 patients had slow heart rate, increased left heart, decreased left ventricular ejection fraction, tissue Doppler imaging showed that the early diastolic peak slowed down in mitral ring. There were 93% (14/15) patients having obvious systolic regurgitation. Conclusion: The time phase, quantity and velocity of diastolic mitral regurgitation have various characteristics, most of them associated with systolic regurgitation combining abnormal cardiac structure and function. Echocardiography provides important information for clinical treatment.
ABSTRACT
To study the chemical constituents from the bark of Myrica rubra, fourteen compounds were isolated from the methanolic extract using various chromatographic techniques, including silica gel, Sephadex LH-20 and preparative HPLC. Their structures were identified on the basis of chemical properties and spectroscopic data, as 3, 5-dimethoxy-4-hydroxymyricanol (1), myricanol (2), myricanone (3), myricanol 11-sulfate (4), myricitrin (5), quercetin (6), quercetin-3-rhamnoside (7), tamarixol (8), uvaol (9), ursolic acid (10), taraxerol (11), myricadiol (12), β-sitosterol (13) and β-daucosterol (14). Among them, compound 1 is a new compound, named as 3, 5-dimethoxy-4-hydroxymyricanol, compounds 8, 9 were isolated from the genus Myrica for the first time.