Biomedical subjects

Yaping Li

Publications and source records attributed to Yaping Li.

10 recordsLinked to original sources

PubMed2025

Landscape and m6A post-transcriptional regulation of soybean proteome.

The soybean is a critical source of vegetable protein, but its proteome remains undercharacterized. Here, we quantify 12,855 proteins across 14 soybean organs using 4D data-independent acquisition mass spectrometry (4D-DIA-MS), creating the most extensive soybean proteome dataset to date. Organ-specific protein expression and co-expression analyses highlight functional specificity with significant differences in protein-transcript abundance across organs. We also map N6-methyladenosine (m6A) modifications, identifying their key role in post-transcriptional protein regulation. Integrative analysis of the proteome and m6A methylome identifies a novel regulator in m6A methylation. This comprehensive proteomic and m6A landscape advances our understanding of soybean biology and provides a valuable resource for crop improvement.

Glycine max↗

PubMed2006

In vitro and in vivo evaluation of donepezil-sustained release microparticles for the treatment of Alzheimer's disease.

The purpose of this work is to prepare donepezil microparticles (DM) and evaluate its advantage as a sustained release delivery system with subcutaneous injection once a month. DM was prepared using poly (d,l-lactide-co-glycolide) (PLGA) by an oil-water emulsion solvent evaporation technique. DM showed the loading ratio 13.2+/-2.1% (w/w) and yield 54.8+/-0.8% with mean particle size about 75mum. In vitro release of DM showed that donepezil completely released within 28 days in water, but the cumulative release percentages up to day 30 were 98.4% and 49.1% for phosphate buffer saline (PBS, pH 5.8) and PBS (pH 7.4), respectively. The in vivo experiment demonstrated that DM (90mg/kg) produced a sustained release process in rats, and reached steady-state concentration at day 8 and maintained until day 27 with steady-state levels of donepezil between 130.3+/-7.8 and 121+/-9.8ng/ml, which was accordance with that of free donepezil by oral application route (3mg/kgday). DM (90mg/kg) by subcutaneous infusion in rats produced the same pharmacological role as free donepezil (3mg/kgday) by oral application route. These results implicated that DM as a sustained release delivery strategy could substitute for its oral formulation for therapy of AD and come true its administration once a month.

Alzheimer Disease↗

PubMed2005

A delivery strategy for rotenone microspheres in an animal model of Parkinson's disease.

In order to study the pathogenesis of Parkinson's disease (PD), and explore therapeutic drug or approaches, the accurate animal model of PD with inexpensive, biocompatible and convenient administration was necessary. The aim of the present work was to investigate a delivery strategy for rotenone microspheres in an animal model of PD. The rotenone microspheres were prepared by solvent evaporation technique. The rotenone microspheres showed high entrapment efficiency (97.4+/-2.2%) with particle size about 100 microm. In vitro release of rotenone microspheres demonstrated different profiles from medium with different pH or concentration of isopropyl alcohol. The most consistent medium with in vivo rotenone levels in rat plasma was PBS (pH 5.8) with 20% isopropyl alcohol, and the cumulated release amount of rotenone over 30 days was 95.4% in it. The rotenone microspheres (9 mg/kg) produced typical PD symptoms in rats, for example, the cataleptic behavior test demonstrated a obviously prolonged descent latency compared with control animals after administration, and the tyrosine hydroxylase (TH) immunohistochemistry tests showed typical histological evidence of selective degeneration of the nigrostriatal dopaminergic system (striatum and substantia nigra) in rotenone microspheres-treated rats. In addition, this delivery system for rotenone model showed many noticeable advantages such as inexpensive, biocompatible and expedient administration by direct subcutaneous injection. This information suggested that rotenone microspheres as a delivery strategy for setting up an ideal animal model of PD was feasible.

Animals↗

PubMed2004

In vitro and in vivo evaluation of actively targetable nanoparticles for paclitaxel delivery.

The aim of the present work was to assess the merits of an actively targetable nanoparticles (ATN), PEG-coated biodegradable polycyanoacrylate nanoparticles (PEG-nanoparticles) conjugated to transferrin, for paclitaxel delivery. PEG-nanoparticles loading paclitaxel were prepared by solvent evaporation technique in advance. ATN were prepared by coupling of transferrin to PEG-nanoparticles. The results showed that the average encapsulation efficiency of ATN was 93.4+/-3.6% with particle size (101.4+/-7.2 nm) and zeta-potential (-13.6+/-1.1 mV). The paclitaxel loaded ATN exhibited a low burst effect with about only 16.2% drug release within the first phase. Subsequently, paclitaxel release profiles displayed a sustained release phase. The amount of cumulated paclitaxel release over 30 days was 81.6%. ATN exhibited a markedly delayed blood clearance in mice, and the paclitaxel level from ATN remained much higher at 24 h compared with that of free drug from paclitaxel injection. The distribution profiles of ATN in S-180 solid tumor-bearing mice after intravenous administration showed the tumor accumulation of paclitaxel increase with time, and the paclitaxel concentration in tumor was about 4.8 and 2.1 times higher than those from paclitaxel injection and PEG-nanoparticles at 6 h after intravenous injection. For mice treated with 20 mg/kg x 5 of ATN, the decrease in body weight was limited within 4% of the initial weight at 5 days after the final administration, and tumor regression was significantly observed with complete tumor regression for five out of nine mice. The tumor burden with ATN-treated mice was much smaller compared with free paclitaxel or NTN-treated mice. In addition, the life span of tumor-bearing mice was significantly increased when they were treated with ATN, in particular, three mice survived over 60 days. Thus, PEG-coated biodegradable polycyanoacrylate nanoparticles conjugated to transferrin could be an effective carrier for paclitaxel delivery.

Animals↗

PubMed2004

Localization of pigment epithelium-derived factor in growing mouse bone.

Pigment epithelium-derived factor (PEDF) is a potent anti-angiogenic factor found in a wide range of fetal and adult tissues, where it is thought to play a role in the regulation of angiogenesis during development. The temporal expression of PEDF during endochondral bone formation has not previously been reported. In this study, we analysed the expression pattern of PEDF in growing mouse hindlimbs from newborn day one through to maturation at week 9, using immunohistochemistry and in situ hybridization. PEDF expression was demonstrated in chondrocytes within the resting, proliferative and upper hypertrophic zones of the epiphyseal growth plate. The pattern of expression was consistent throughout the developmental stages of the mouse. In addition, PEDF was expressed by osteoblasts lining the bone spicules in the ossification zone of metaphyseal bone, as well as by osteoblasts lining cortical periosteum. These novel results demonstrate that PEDF is developmentally expressed in both cartilage and bone cells during endochondral bone formation, and strongly suggest that it may play a regulatory role in the processes of chondrocyte and osteoblast differentiation, endochondral ossification, and bone remodelling during growth and development of long bones.

Animals↗

PubMed2004

Determination of paeoniflorin in rat hippocampus by high-performance liquid chromatography after intravenous administration of Paeoniae Radix extract.

A rapid and simple high-performance liquid chromatographic (HPLC) assay for the determination of paeoniflorin in rat hippocampus was developed in this study. The chromatographic analysis was carried out using reversed-phase isocratic elution with a Zorbax SB-C(18) column, a mobile phase of methanol-water (32:68, v/v), and detection by ultraviolet (UV) absorption at 233 nm. The lower limits of quantitation (LLQ) were 1 microg/ml for paeoniflorin. The calibration curve for paeoniflorin was linear (r = 0.9999) over the concentration range of 1-50 microg/ml. The coefficients of variation of intra- and inter-day assays were 7.00, 0.58, 1.46% and 5.48, 1.79, 1.70% at concentrations of 1, 10, 50 microg/ml, respectively. The recoveries of paeoniflorin from rat hippocampus were 98.28 +/- 2.14, 98.96 +/- 1.48, and 95.34 +/- 0.92 at concentrations of 1, 10 and 50 microg/ml, respectively. Stability studies showed that paeoniflorin was stable at temperatures of 2-8 degrees C in methanol for at least 20 days. The method was applied to determine the time course of paeoniflorin in rat hippocampus, following the administration of a 60 mg/kg i.v. dose of paeoniflorin in Paeoniae Radix extract to a male Wistar rat.

Animals↗

PubMed2004

Stability and release characteristics of poly(D,L-lactide-co-glycolide) encapsulated CaPi-DNA coprecipitation.

The aims of this work were to determine the stability of DNA-calcium-phosphate coprecipitation (CaPi-DNA) against various conditions during double emulsification microencapsulation and assess the release and physicochemical characteristics of poly(D,L-lactide-co-glycolide) (PLGA) microparticles loading CaPi-DNA. CaPi-DNA prepared at pH 6.5 showed a good stability with over 60% CaPi-DNA remained after emulsification, but no more than 40% at pH 8.0. Polyvinyl alcohol (PVA, 1-5%) could make over 80% CaPi-DNA (pH 7.0) preserved after homogenization. The dichloromethane (DCM), mixture of DCM and ethyl acetate, ether and n-hexane (1:1) exhibited neglectable influence on CaPi-DNA under homogenization. PLGA had influenced on CaPi-DNA without any additional stabilizer, in particular, PLGA (75:25, 4%, w/v) demonstrated a profound damage with only about 10% of the original CaPi-DNA remained. PLGA microparticles loading CaPi-DNA were spherical in shape with size range of 2.0-5.0microm, and entrapment efficiency 30-50%. CaPi-DNA was found to increase the stability of pDNA in PLGA microparticles without losing its structure integrity. The release of CaPi-DNA from microparticles showed a low burst release (<7.5%) within 24h and following sustained release process. The amount of cumulated CaPi-DNA release over 30 days was: 17.6% for PLGA (lactide:glycolide=50:50), 27.3% for PLGA (65:35) and 44.8% for PLGA (75:25) microparticles, respectively. The encapsulation of CaPi-DNA in microparticles could significantly protect CaPi-DNA from degradation of nuclease with average over 80% of total DNA recovery. These results suggested that the encapsulation of CaPi-DNA in PLGA microparticles could improve stability of pDNA.

Calcium Phosphates↗

PubMed2004

Effects of cerebral ischemia-reperfusion on pharmacokinetic fate of paeoniflorin after intravenous administration of Paeoniae Radix extract in rats.

The objective of the present study was to investigate the effects of cerebral ischemia-reperfusion on pharmacokinetics of paeoniflorin after intravenous administration of Paeoniae Radix extract (PRE) in rats. The cerebral ischemia-reperfusion rats were induced by occluding the bilateral carotid arteries of normal rats for 2 h, followed by reperfusion. The resultant animals were immediately administrated by PRE (at a dose of 60 mg/kg of paeoniflorin) via the femoral vein, whilst the same dose was injected to the normal rats. Plasma samples were collected at different time to construct pharmacokinetic profiles by plotting drug concentration versus time. Quantification of paeoniflorin in rat plasma was achieved by using a simple and rapid high-performance liquid chromatographic method. In normal rats, the major parameters of distribution half-life (t1/2alpha), elimination half-life (t1/2beta), area under the plasma concentration-time (AUC), mean retention time (MRT), and clearance (CL), estimated by an open two-compartmental model, were 0.69, 18.77 min, 5338.71 (microg min)/ml, 18.13 min and 0.0162 mg/(kg min), respectively. However, in ischemia-reperfusion rats, the corresponding parameters were 2.04, 24.51 min, 9626.00 (microg min)/ml, 29.75 min and 0.0071 mg/(kg min), respectively. The results showed that ischemia- reperfusion significantly increased AUC values, decreased CL values, and prolonged the terminal half-life of paeoniflorin. These findings suggest that the injuries of ischemia-reperfusion could play an important role in pharmacokinetic process of paeoniflorin.

Animals↗

PubMed2003

Nanoparticles bearing polyethyleneglycol-coupled transferrin as gene carriers: preparation and in vitro evaluation.

The aims of this work were to determine the stability of pDNA against various conditions during microencapsulation, prepare transferrin (TF)-conjugated PEGylated polycyanoacrylate nanoparticles (TF-PEG-nanoparticles), and assess its physicochemical characteristics and in vitro targeting cells association. The open circular forms of pDNA obviously increased when pDNA was emulsified into organic solution under sonification. When pDNA solution (pH 7.0) contained 1, 3 or 5% (w/v) PVA, after sonification, average 48.2, 59.4 and 62.1% of double-supercoiled DNA (dsDNA) were preserved, respectively. When medium of pDNA was 0.9% NaCl (pH 7.0), 0.1M NaHCO(3) (pH 8.0) or phosphate buffer (pH 8.0), average 53.1, 69.3 and 56.9% of dsDNA remained after sonification, respectively. Poly(aminopoly(ethylene glycol)cyanoacrylate-co-hexadecyl cyanoacrylate) (poly(H(2)NPEGCA-co-HDCA)) showed a slight influence on pDNA in 0.1M NaHCO(3) (pH 8.0) when its concentration increased from 0.5 to 4% (w/v). TF-PEG-nanoparticles loading pDNA were spherical in shape with size under 200nm and entrapment efficiency 35-50%. 0.1M NaHCO(3) with 3% PVA (w/v) could largely reduce the damage of pDNA during microencapsulation. TF-PEG-nanoparticles bore 1-3% of the total PEG chains conjugated to TF molecules, and exhibited the burst effect with over 30% drug release within 1 day. After the first phase, pDNA release profiles displayed a sustained release. The amount of cumulated pDNA release over 7 days was: 86.3, 81.5 and 74.4% for 1, 2 and 4% polymer nanoparticles, respectively. The degree of target K562 cell binding of TF-PEG-nanoparticles was greater than that of non-targeted PEG-nanoparticles at 4 degrees C. The presence of free TF decreased significantly the degree of cell binding of TF-PEG-nanoparticles, which revealed that the binding of TF-PEG-nanoparticles to K562 cells was indeed receptor specific. These results suggested that TF-PEG-nanoparticles were useful for delivery of pDNA to target cells.

Buffers↗

PubMed2001

Synthesis of

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Journal Article↗