Pharmacokinetic and pharmacodynamic profiles of recombinant human erythropoietin-loaded poly(lactic-co-glycolic acid) microspheres in rats.

AIM: To characterize the pharmacokinetic and pharmacodynamic profiles of the recombinant human erythropoietin (rhEPO)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres in rats. METHODS: The rhEPO-loaded microspheres were prepared using a solid-in-oil-in-water emulsion method. Pharmacokinetics and pharmacodynamics of the rhEPO-loaded microspheres were evaluated in male Sprague-Dawley rats. The serum rhEPO level was determined with ELISA. The level of anti-rhEPO antibody in the serum was measured to assess the immunogenicity of rhEPO released from the microspheres. RESULTS: rhEPO was almost completely released from the PLGA microspheres in vitro, following zero-order release kinetics over approximately 30 d. After intramuscular injection (10,000 or 30,000 IU rhEPO/kg) in the rats, the serum rhEPO concentration reached maximum levels on d 1, then decreased gradually and was maintained at nearly steady levels for approximately 4 weeks. Furthermore, the release of rhEPO from the PLGA microspheres was found to be controlled mainly by a dissolution/diffusion mechanism. A good linear correlation (R(2)=0.98) was obtained between the in vitro and in vivo release data. A single intramuscular injection of the rhEPO-loaded PLGA microspheres (10,000 or 30,000 IU rhEPO/kg) in the rats resulted in elevated hemoglobin and red blood cell concentrations for more than 28 d. Moreover, the immunogenicity of rhEPO released from the PLGA microspheres was comparable with that of the unencapsulated rhEPO. CONCLUSION: The results prove the feasibility of using the PLGA-based microspheres to deliver rhEPO for approximately 1 month.

Hepatic Macrophage activation and the LPS pathway in patients with different degrees of severity and histopathological patterns of drug induced liver injury.

BACKGROUND: Inflammatory activation of hepatic macrophages plays a primary role in drug-induced liver injury (DILI). However, the exact mechanism underlying DILI remains unclear. METHODS: A total of 328 DILI patients and 80 healthy individuals were prospectively enrolled in this study. The DILI patients were categorized into subgroups based on either disease severity or histopathological patterns. Plasma soluble CD163 (sCD163) and hepatic CD163 were examined to determine hepatic macrophage activation, and CD8, CD20, and MUM-1 were assessed to determine cellular immunity using immunohistochemistry. The lipopolysaccharide (LPS) pathway proteins [e.g. LPS, soluble CD14 (sCD14), and LPS-binding protein (LBP)] were measured using enzyme-linked immunosorbent assay. RESULTS: Plasma sCD163 levels were nine-fold higher in DILI patients than in healthy controls at the baseline, but significantly decreased at the 4-week follow-up visit after treatment. The numbers of hepatic macrophages, B cells, and plasma cells were significantly higher in the liver tissues from DILI patients than those from healthy controls. Furthermore, the baseline levels of LPS pathway proteins in the DILI patients were significantly higher than those in the controls. Notably, these proteins significantly decreased at the 4-week follow-up visit but remained significantly higher than the levels for the controls. CONCLUSIONS: Hepatic inflammation in DILI involves the activation of hepatic macrophages and cellular immunity, in which the LPS pathway likely plays a role, at least in part. As such, this study has improved our understanding of the pathological mechanisms for DILI and may facilitate the development of better treatments for patients with DILI.

Yiqi Huoxue Recipe Improves Liver Regeneration in Rats after Partial Hepatectomy via JNK Pathway.

The liver is the only visceral organ that exhibits a remarkable capability of regenerating in response to partial hepatectomy (PH) or chemical injury. Improving liver regeneration (LR) ability is the basis for the favourable treatment outcome of patients after PH, which can serve as a potential indicator for postoperative survival. The present study aimed to investigate the protective effects of Yiqi Huoxue recipe (YQHX) on LR after PH in rats and further elucidate its underlying mechanism. A two-thirds PH rat model was used in this study. Wistar rats were randomly divided into four groups: sham-operated, PH, YQHX + PH, and Fuzheng Huayu decoction (FZHY) + PH groups. All rats were sacrificed under anesthesia at 24 and 72 h after surgery. The rates of LR were calculated, and the expression levels of cyclin D1 and c-jun were determined by immunohistochemical staining. The protein levels of p-JNK1/2, JNK1/2, p-c-jun, c-jun, Bax, and Bcl-2 were detected by Western blotting, while the mRNA levels of JNK1, JNK2, c-jun, Bax, and Bcl-2 were examined by real-time polymerase chain reaction (RT-PCR). At the corresponding time points, YQHX and FZHY administration dramatically induced the protein levels of p-JNK1/2 compared to the PH group (p < 0.05), while FZHY + PH group showed prominently increase in p-JNK1/2 protein levels compared to the YQHX + PH group (p < 0.05). A similar trend was observed for the expression levels of p-c-jun. Compared to the PH group, YQHX and FZHY markedly reduced the mRNA and protein expression levels of Bax at 24 h after PH, while those in the FZHY + PH group decreased more obviously (p < 0.05). Besides, in comparison with the PH group, YQHX and FZHY administration predominantly upregulated the mRNA and protein expression levels of Bcl-2 at 24 and 72 h after PH (p < 0.05). In conclusion, YQHX improves LR in rats after PH by inhibiting hepatocyte apoptosis via the JNK signaling pathway.

Gamma-glutamyl transpeptidase to platelet ratio index is a good noninvasive biomarker for predicting liver fibrosis in Chinese chronic hepatitis B patients.

Objective To evaluate whether gamma-glutamyl transpeptidase to platelet ratio index (GPRI) can diagnose the extent of liver fibrosis in Chinese patients with chronic hepatitis B (CHB) infection. Methods This prospective observational study used liver biopsy results as the gold standard to evaluate the ability of GPRI to predict hepatic fibrosis compared with two other markers, the aspartate aminotransferase (AST) to platelet ratio index (APRI) and fibrosis-4 score (FIB-4). The clinical and demographic factors that affected GPRI, independent of liver fibrosis, were assessed using multivariate linear regression analyses. Results This study enrolled 312 patients with CHB. GPRI had a significantly positive correlation with liver fibrosis stage and the correlation coefficient was higher than that for APRI and FIB-4. The areas under the receiver operating curves for GPRI for significant fibrosis, bridging fibrosis, and cirrhosis were 0.728, 0.836, and 0.842, respectively. Of the three indices, GPRI had the highest diagnostic accuracy for bridging fibrosis and cirrhosis. Age, elevated AST and elevated total bilirubin levels were independent determinants of increased GPRI. Conclusion GPRI was a more reliable laboratory marker than APRI and FIB-4 for predicting the stage of liver fibrosis in Chinese patients with CHB.

Magnetic polycarbonate microspheres for tumor-targeted delivery of tumor necrosis factor.

OBJECTIVE: The specific expression of transferrin receptor can represent a diagnostic tool or therapeutic target in solid tumors expressing this antigen. Herein, the human transferrin receptor monoclonal antibody (T9) was investigated as a tumor-targeting group for active targeted-drug delivery systems. MATERIALS AND METHODS: A tumor-targeted conjugate T9-TNF was synthesized by the attachment of both human transferrin receptor monoclonal antibody (T9) as a tumor-targeting group and human tumor necrosis factor-α (TNF) as an anti-cancer drug to two terminated hydroxyl groups of poly(ethylene glycol). Subsequently, a solvent evaporation technique was adopted to produce anti-cancer magnetic polymer microspheres T9-TNF-PC-M containing T9-TNF and Fe3O4 magnetic ultrafine powders (M) using poly(trimethylene carbonate-co-5,5-dimethyl trimethylene carbonate) (PC, P(TMC-co-DTC)) as a polymeric carrier. RESULTS AND DISCUSSION: These magnetic polycarbonate microspheres possessed a steady TNF release rate in phosphate buffer saline solution, strong magnetic responsiveness and high T9-TNF loading capacity. In vitro cytotoxicity assays demonstrated the microspheres T9-TNF-PC-M and conjugate T9-TNF were strongly inhibitory to the human hepatic carcinoma (Bel-7204) cells. In vivo site-specific therapy in nude mice with human hepatic carcinoma indicated that the microspheres T9-TNF-PC-M and conjugate T9-TNF possessed markedly higher anti-tumor activity against Bel-7204 in mice than that of TNF. CONCLUSIONS: These results indicated that the magnetic polycarbonate microspheres were suitable as the potential-targeted treatment for hepatic carcinoma therapeutics.