OBJECTIVE To optimize the formulation for sustained-release particles of matrine(MAT) and paeonol(PAE) and to primarily evaluate their quality. METHODS The sustained-release particles were fabricated by the extrusion-spheronization method. Single factor analysis was conducted on the main sustained-release materials and their dosage, auxiliary sustained-release materials, and the total amount and proportion of mixed sustained-release materials, using the cumulative release rates of MAT and PAE in vitro as evaluation indicators. By combining central composition design-response surface methodology, the formulation of sustained-release materials was optimized, and the effects of the total amount and mass ratio of ethyl cellulose(EC) and chitosan(CS) on the cumulative release rate and release synchronization of MAT and PAE were investigated. The formulation characteristics, in vitro release, and preliminary stability tests of MAT-PAE-SRPs were evaluated, and the release process kinetic equation was fitted. RESULTS The optimized formulation contained 23.5% EC and 17.1% CS as sustained-release materials. The yield, repose angle, bulk density and friability of final particles were 97.23%, 38.1°, 0.74 g·mL−1 and 0.74%, respectively. The particles showed sustained release pattern in various media and released faster in acidic media with its release percentage >90% at 12 h. The release profile of MAT was fitted best with first order equation, and that of paeonol with Higuchi equation. The formation of SRPs improved the stability of both drugs. CONCLUSION The sustained-release effect of MAT-PAE-SRPs prepared by sustained-release materials EC and CS is significant, and the cumulative release rate and release synchronization of MAT and PAE are good, which can provide reference for the research of dual loaded sustained-release formulations.

Thymosin β4 (Tβ4) is a key factor in cardiac development, growth, disease, epicardial integrity, blood vessel formation and has cardio-protective properties. However, its role in murine embryonic stem cells (mESCs) proliferation and cardiovascular differentiation remains unclear. Thus we aimed to elucidate the influence of Tβ4 on mESCs. Target genes during mESCs proliferation and differentiation were detected by real-time PCR or Western blotting, and patch clamp was applied to characterize the mESCs-derived cardiomyocytes. It was found that Tβ4 decreased mESCs proliferation in a partial dose-dependent manner and the expression of cell cycle regulatory genes c-myc, c-fos and c-jun. However, mESCs self-renewal markers Oct4 and Nanog were elevated, indicating the maintenance of self-renewal ability in these mESCs. Phosphorylation of STAT3 and Akt was inhibited by Tβ4 while the expression of RAS and phosphorylation of ERK were enhanced. No significant difference was found in BMP2/BMP4 or their downstream protein smad. Wnt3 and Wnt11 were remarkably decreased by Tβ4 with upregulation of Tcf3 and constant β-catenin. Under mESCs differentiation, Tβ4 treatment did not change the expression of cardiovascular cell markers α-MHC, PECAM, and α-SMA. Neither the electrophysiological properties of mESCs-derived cardiomyocytes nor the hormonal regulation by Iso/Cch was affected by Tβ4. In conclusion, Tβ4 suppressed mESCs proliferation by affecting the activity of STAT3, Akt, ERK and Wnt pathways. However, Tβ4 did not influence the in vitro cardiovascular differentiation.
Animals ; Cell Cycle ; drug effects ; genetics ; Cell Differentiation ; drug effects ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Gene Expression Regulation ; drug effects ; JNK Mitogen-Activated Protein Kinases ; genetics ; metabolism ; Mice ; Mouse Embryonic Stem Cells ; cytology ; drug effects ; metabolism ; Myocytes, Cardiac ; cytology ; drug effects ; metabolism ; Nanog Homeobox Protein ; genetics ; metabolism ; Octamer Transcription Factor-3 ; genetics ; metabolism ; Patch-Clamp Techniques ; Primary Cell Culture ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Proto-Oncogene Proteins c-fos ; genetics ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; STAT3 Transcription Factor ; genetics ; metabolism ; Signal Transduction ; Thymosin ; pharmacology