Puerarin Loaded PLGA Nanoparticles: Optimization Processes of Preparation and Anti-alcohol Intoxication Effects in Mice.

To improve the bioavailability of puerarin in liver, the optimized preparation method of puerarin-PLGA nanoparticles (Pue-PLGA-nps) and the effect of Pue-PLGA-nps on alcoholism mice were studied. The preparation of Pue-PLGA-nps was optimized by the Box-Behnken design and response surface methodology (RSM). To estimate the anti-alcoholism of Pue-PLGA-nps in vivo, drunkenness incubation period and sober time of mice were detected, and Morris water maze (MWM) test was performed. AST, ALT, and SOD were used to determine the damages and oxidative stress in the liver, as well as histopathological observation of the liver. The optimal preparation conditions of Pue-PLGA-nps in RSM were as follows: the drug-material ratio was 1:1.4, the reaction temperature was 65°C, and the reaction time was 13 min. The drug entrapment efficiency of Pue-PLGA-nps was 90.6% and closely up to 98.9% of the standard prediction value. The results in vivo showed that the Pue-PLGA-nps significantly increased the drunkenness incubation period in comparison with the model group and decreased drunkenness sober time and landing time in MWM in comparison with the model group and puerarin group (P<0.05) . The contents of AST and ALT in the liver of Pue-PLGA-nps group were significantly lower than those of model group and Puerarin group (P<0.05), and the activity of SOD in the liver of Pue-PLGA-nps group was higher than that of model group (P<0.05). By histopathological observation, moreover, Pue-PLGA-nps significantly attenuated the impairment of the liver caused by alcoholism. In conclusion, through BBD and RSM, the process conditions of the Pue-PLGA-nps were successfully optimized. The Pue-PLGA-nps exerted higher bioavailability and better effect of anti-alcoholism than puerarin, indicating PLGA nanoparticles could be potential to deliver drug.

Folate-decorated and reduction-sensitive micelles assembled from amphiphilic polymer-camptothecin conjugates for intracellular drug delivery.

It is one of the challenges for a wide clinical application of polymer micelles to address the structure disintegration and premature drug release before reaching a pathological site. In the current study, folic acid (FA)-decorated polymer-drug conjugates (FSC) were synthesized with disulfide linkages between camptothecin (CPT) and amphiphilic poly(ethylene glycol)-b-poly(ε-caprolactone) (PECL) copolymers. FSC conjugates were proposed to assemble into micelles with a hydrophobic core of PCL segments and CPT and a hydrophilic corona of PEG segments. The addition of hexadecanol during micelle formation (FSC-16) was proposed to modulate the interactions of hydrophobic segments in micelles and enhance the reductive sensitivity. FSC-16 micelles were obtained with critical micelle concentration of around 2 µg/mL and an average size of around 200 nm, and the conjugated CPT was rapidly released out in response to glutathione. The reductive sensitivity was also demonstrated with respect to the changes of micelle size and morphologies as well as the fluorescent intensity of pyrene loaded in micelles. Benefiting from the FA receptor-mediated uptake and the reduction-sensitive release of CPT, significant cytotoxicity and cell apoptosis were identified for FSC-16 micelles against SKOV-3 cells with strong expressions of FA receptors. Flow cytometry and confocal laser scanning microscopy analyses demonstrated that CPT was distributed into nuclei after cellular uptake and intracellular release from FSC-16 micelles. Thus, the FA-decorated and reduction-sensitive micelles assembled from polymer-drug conjugates show advantages in inhibiting premature release during circulation, enhancing cellular uptake at the tumor tissues, and promoting intracellular release and nuclei location of the active moieties.

Long-term Pegylated GH for Children With GH Deficiency: A Large, Prospective, Real-world Study.

CONTEXT: The evidence of long-term polyethylene glycol recombinant human GH (PEG-rhGH) in pediatric GH deficiency (GHD) is limited. OBJECTIVE: This study aimed to examine the effectiveness and safety of long-term PEG-rhGH in children with GHD in the real world, as well as to examine the effects of dose on patient outcomes. DESIGN: A prospective, observational, posttrial study (NCT03290235). SETTING, PARTICIPANTS AND INTERVENTION: Children with GHD were enrolled from 81 centers in China in 4 individual clinical trials and received weekly 0.2 mg/kg/wk (high-dose) or 0.1 to <0.2 mg/kg/wk (low-dose) PEG-rhGH for 30 months. MAIN OUTCOMES MEASURES: Height SD score (Ht SDS) at 12, 24, and 36 months. RESULTS: A total of 1170 children were enrolled in this posttrial study, with 642 patients in the high-dose subgroup and 528 in the low-dose subgroup. The Ht SDS improved significantly after treatment in the total population (P < 0.0001), with a mean change of 0.53 ± 0.30, 0.89 ± 0.48, 1.35 ± 0.63, 1.63 ± 0.75 at 6 months, 12 months, 24 months, and 36 months, respectively. In addition, the changes in Ht SDS from baseline were significantly improved in the high-dose subgroup compared with the low-dose subgroup at 6, 12, 24, and 36 months after treatment (all P < 0.05). A total of 12 (1.03%) patients developed serious adverse events. There was no serious adverse event related to the treatment, and no AEs leading to treatment discontinuation or death occurred. CONCLUSIONS: PEG-rhGH showed long-term effectiveness and safety in treating children with GHD. Both dose subgroups showed promising outcomes, whereas PEG-rhGH 0.2 mg/kg/wk might show additional benefit.

Tissue-engineered esophagus: recellular esophageal extracellular matrix based on perfusion-decellularized technique and mesenchymal stem cells.

Perfusion-decellularization was an interesting technique to generate a natural extracellular matrix (ECM) with the complete three-dimensional anatomical structure and vascular system. In this study, the esophageal ECM (E-ECM) scaffold was successfully constructed by perfusion-decellularized technique through the vascular system for the first time. And the physicochemical and biological properties of the E-ECM scaffolds were evaluated. The bone marrow mesenchymal stem cells (BMSCs) were induced to differentiate into myocytesin vitro. E-ECM scaffolds reseeded with myocytes were implanted into the greater omenta to obtain recellular esophageal ECM (RE-ECM), a tissue-engineered esophagus. The results showed that the cells of the esophagi were completely and uniformly removed after perfusion. E-ECM scaffolds retained the original four-layer organizational structure and vascular system with excellent biocompatibility. And the E-ECM scaffolds had no significant difference in mechanical properties comparing with fresh esophagi,p> 0.05. Immunocytochemistry showed positive expression ofα-sarcomeric actin, suggesting that BMSCs had successfully differentiated into myocytes. Most importantly, we found that in the RE-ECM muscularis, the myocytes regenerated linearly and continuously and migrated to the deep, and the tissue vascularization was obvious. The cell survival rates at 1 week and 2 weeks were 98.5 ± 3.0% and 96.4 ± 4.6%, respectively. It was demonstrated that myocytes maintained the ability for proliferation and differentiation for at least 2 weeks, and the cell activity was satisfactory in the RE-ECM. It follows that the tissue-engineered esophagus based on perfusion-decellularized technique and mesenchymal stem cells has great potential in esophageal repair. It is proposed as a promising alternative for reconstruction of esophageal defects in the future.

Synergistic antitumor efficacy of redox and pH dually responsive micelleplexes for co-delivery of camptothecin and genes.

Challenges remain to load and deliver two or multiple drugs of complementary effects for synergistic cancer therapies. In the current study, multiarmed amphiphilic copolymers of 4-arm poly(ethylene glycol) (PEG) and polyaspartate (PAsp) are created for conjugation of camptothecin (CPT) and condensation with tumor necrosis factor-α (TNF) plasmids. Diethylenetriamine (DET) is grafted on PAsp, and CPT is conjugated onto PAsp(DET) by disulfide linkages to form hydrophobic cores of micelles, followed by condensation with TNF plasmids to form micelleplexes. The cis-aconitic linkers are introduced between PEG and PAsp(DET) to remove PEG shells in response to acidic pH, resulting in destabilized micelleplexes and prompted endosomal escape into the cytosol. The micelleplex disintegration in response to reductive stimuli in the cytosol leads to an efficient CPT release and pDNA disassociation. The co-delivery of CPT with TNF plasmids enhances the gene transfection of micelleplexes at low N/P ratios, and shows synergetic cytotoxicities to tumor cells with 2.5 and 8 folds lower IC50s compared with those after treatment with CPT or TNF alone, respectively. The micelleplex treatment on 4T1 tumor models dramatically extends the animal survival and suppresses the tumor growth with 2.3 and 3 folds lower in volume compared with CPT or TNF treatment alone, respectively. Histological and biochemical analyses display TNF expressions in tumor tissues after micelleplex treatment, resulting in significantly larger necrotic regions in tumors, higher cell apoptosis rates, and no obvious sign of tumor metastasis in lungs compared with other treatment. Therefore, the multifunctional micelleplexes based on multiarmed PEG-PAsp(DET) copolymers offer the targeted drug/gene delivery, dually responsive drug/gene release and synergistic antitumor efficacy, holding great promises for combination therapies. STATEMENT OF SIGNIFICANCE: Micelleplexes are constructed from multiarmed amphiphilic copolymers with conjugation of captothecin (CPT) and condensation of tumor necrosis factor-α (TNF) plasmid. The pH/redox stimuli realize co-delivery of CPT and pDNA in a sequential manner of folate-mediated endocytosis, endosomal escape induced by PEG cleavage, reduction-sensitive release of CPT in cytosol, and pDNA release from disintegrated polyplexes after CPT release. Compared with CPT or TNF treatment alone, the micelleplexes achieve 2.5 and 8 folds higher cytotoxicities to tumor cells, and suppress the tumor growth with 2.3 and 3 folds lower in volume, respectively. It demonstrates a feasible strategy to develop multifunctional micelleplexes with simultaneous drug conjugation and pDNA condensation, dually responsive drug/gene release and synergistic antitumor efficacy, holding great promise for combinational therapies.

Shape effects of electrospun fiber rods on the tissue distribution and antitumor efficacy.

The significant impact of drug-loaded nanocarriers on cancer chemotherapy lies in the ability to specifically target to tumors with alleviated systemic toxicities. In the current study, a versatile and scalable method has been developed to construct fiber rods from electrospun fibers by ultrasonication using encapsulated NaCl nanoparticles as void-precursors. The shape effects of doxorubicin (DOX)-loaded fiber rods with an average diameter of around 500nm and different lengths are determined on the blood circulation, tumor accumulation and cellular uptake. Compared with microspheres, fiber rods indicate an up to 4-fold higher accumulation in tumors and an up to 3-fold longer terminal half-life of plasma DOX levels after intravenous injection. Fiber rods with shorter lengths show a significantly higher in vitro cytotoxicity to tumor cells, a higher DOX accumulation and cell necrosis in tumors, and a significantly lower metastasis in lungs. Among fiber rods with different lengths, fiber rods with an average length of 2µm induce significantly higher inhibition on tumor cell proliferation and induction of cell apoptosis, as wells as no detectable metastatic nodules in lung sections. Therefore, the shape effects of electrospun fiber rods hold great potential for enhancing systemic circulation and directing biodistribution to improve therapeutic outcomes.

Pharmacokinetics and antitumor efficacy of micelles assembled from multiarmed amphiphilic copolymers with drug conjugates in comparison with drug-encapsulated micelles.

The premature drug release and structural dissociation before reaching pathological sites have posed major challenges for self-assembled micelles. To address these challenges, star-shaped amphiphilic copolymers derived from 4-armed poly(ethylene glycol) (PEG) were proposed for chemical conjugation of chemotherapeutic drugs and assembly into drug-conjugated micelles (DCM) with reductive sensitivity. The current study aimed to elucidate the in vitro and in vivo performance of DCM and a comparison with conventional drug-encapsulated micelles (DEM) was initially launched. DEM carriers were constructed with a similar structure to DCM from 4-armed PEG, and disulfide linkages were located between the hydrophilic and hydrophobic segments. Both DCM and DEM had an average size of around 130 nm, camptothecin (CPT) loadings of around 7.7% and critical micelle concentrations of around 0.95 µg/ml. Compared with DEM, DCM showed a lower initial drug release, a lower sensitivity of drug release to glutathione, and a higher structural stability after incubation with human serum albumin (HSA). The CPT derivatives (CPT-SH) released from DCM indicated cytotoxicities similar to CPT and remained a higher lactone stability than CPT in the presence of HSA. DCM showed slightly higher cytotoxicities to 4T1 cells and significantly lower cytotoxicities to normal cells than DEM. Pharmacokinetic analyses after intravenous administration of DCM indicated around 2.65 folds higher AUC0-∞, 2.66 folds lower clearance, and 1.87 folds higher tumor accumulation than those of DEM. In addition to a less disturbance to hematological and biochemical parameters and a lower acute toxicity to small intestines, DCM showed more significant tumor suppression efficacy and less tumor metastasis to lungs than DEM. It is suggested that DCM could overcome the limitation of conventional micelles by alleviating the premature drug release during blood circulation, relieving the systemic toxicity and promoting the therapeutic efficacy.

Antimetastasis and antitumor efficacy promoted by sequential release of vascular disrupting and chemotherapeutic agents from electrospun fibers.

The vasculature in tumor microenvironment plays important roles in the tumor growth and metastasis, and the combination of vascular disrupting agents with chemotherapeutic drugs should be effective in inhibiting tumor progression. But the dosing schedules are essential to achieve a balance between vascular collapse and intratumoral uptake of chemotherapeutic agents. In the current study, emulsion and blend electrospinning were used to create compartmental fibers accommodating both combretastatin A-4 (CA4) and hydroxycamptothecin (HCPT). The release durations of CA4 and HCPT were modulated through the structure of fibers for dual drug loadings and the inoculation of 2-hydroxypropyl-ß-cyclodextrin in fiber matrices. Under a noncontact cell coculture in Transwell, the sequential release of CA4 and HCPT indicated a sequential killing of endothelial and tumor cells. In an orthotopic breast tumor model, all the CA4/HCPT-loaded fibers showed superior antitumor efficacy and higher survival rate than fibers with loaded individual drug. Compared with fibrous mats with infiltrated free CA4 and fibers with extended release of CA4 for over 30 days, fibers with sustained release of CA4 for 3-7 days from CA4/HCPT-loaded fibers resulted in the most significant antitumor efficacy, tumor vasculature destruction, and the least tumor metastasis to lungs. A judicious selection of CA4 release durations in the combination therapy should be essential to enhance the tumor suppression efficacy and antimetastasis activity.

[Endoscope-assisted superficial parotidectomy via retroauricular hairline approach: anatomical study].

OBJECTIVE: To provide anantomical basis for the endoscope-assisted partial superficial parotidectomy via retroauricular hairline approach (EASPRHA) and assess its feasibility and safety. METHOD: The surgical anatomy of retroauricular hairline region and parotid gland region were observed in 15 fresh human cadavers (30 halves). The EASPRHA was performed on 5 human cadavers (10 halves). After the procedure, the related vascular and neural structures were evaluated. RESULT: The retroauricular hairline region extends between superficial musculoaponeurotic system and superficial cervical fascia. On the superficial surface of the upper sternocleidomastoid lie the lesser occipital nerve, the great auricular nerve and the external jugular vein. The bifurcation of great auricular nerve is(22.85 ± 2.01) mm from the bottom of earlobe. The parotid gland region extends between parotidomassteric fascia and parotid gland parenchyma. The facial nerve emerging from the stylomastoid foramen runs across the superficial surface of base of styloid process, passes through the interspace between cartilage of external acoustic meatus and posterior belly of digastric muscle, and enters the parotid gland. The bifurcation of facial nerve trunk is (19.10 ± 3.10)mm from the mastoidale and (39.49 ± 5.78) mm from the mandibular angle. Above the posterior belly of digastric muscle, the posterior auricular artery arises from the posterior wall of the external carotid artery with its main stem running over the superficial surface of facial nerve trunk. In all endoscope-assisted operations, the partial superficial parotidectomy was successful without the need for an additional incision. No major neurovascular damage wasobserved. CONCLUSION: A thorough knowledge of the surgical anatomy of retroauricular hairline region and parotid gland region is an essential requirement in performing the safe and feasible EASPRHA.

Promoted antitumor activities of acid-labile electrospun fibers loaded with hydroxycamptothecin via intratumoral implantation.

The acidosis of tumor microenvironments is one of the universal phenomena of solid tumors, and the increased acidity may be in fact essential intermediates in the progression of tumor growth and several lethal phenotypic traits of tumors, such as invasion and metastasis. Acid-labile polymers PBELA with incorporating acetal groups into biodegradable backbone of poly(d,l-lactide)-poly(ethylene glycol) (PELA) were utilized to load hydroxycamptothecin (HCPT) into electrospun fibers for intratumoral chemotherapy. Compared with that under a simulated physiological condition of pH 7.4, the incubation of PBELA fibers in acidic media resulted in larger mass loss and molecular weight reduction of fiber matrices and enhanced HCPT release from fibers. In vitro cytotoxicity assay of HCPT-loaded PBELA fibers indicated 6-fold higher inhibitory activity against HepG2 cells after incubation in pH 6.8 media than that of pH 7.4, while there was no significant difference for free HCPT and HCPT-loaded PELA fibers. The tumor growth, tumor cell apoptosis, and animal survival rate after intratumoral implantation of HCPT-loaded PBELA fibers indicated a superior in vivo antitumor activity and fewer side effects than other treatment. Therefore, acid-labile electrospun fibers may be promising implants for localized therapy of inoperable tumors and for prevention of post-surgical tumor recurrence.

Antitumor activities of emulsion electrospun fibers with core loading of hydroxycamptothecin via intratumoral implantation.

Emulsion electrospinning was used in the present study to prepare core-sheath structured fibers with core-loading of hydroxycamptothecin (HCPT), and their antitumor activities were evaluated both in vitro on cancer cell lines and in vivo on tumor bearing mice via intratumoral implantation. Compared with our previous investigation on blend electrospun fibers, the addition of 2-hydroxypropyl-ß-cyclodextrin (HPCD) and the preferential formation of HPCT/HPCD inclusion complexes resulted in significantly faster HCPT release from and higher degradation rate of emulsion electrospun fibers. The core-sheath structure led to around 93% of lactone form remaining after emulsion electrospinning and incubation in buffer solutions for over one month. In vitro cytotoxicity tests on HCPT-loaded electrospun fibers indicated over 20 times higher inhibitory activity against HepG2 cells than free HCPT during 72h incubation. Hepatoma H22 cells were subcutaneously injected into Kunming mice to form solid tumors for in vivo tests on the antitumor efficacy. Based on the tumor volume, survival rate and body weight changes, HCPT-loaded fibers indicated superior in vivo antitumor activities to and fewer side effects than free HCPT. The histopathological staining and immunohistochemical examinations of caspase-3 expression indicated more necrosis and apoptosis induced by HCPT-loaded fibers. The above results demonstrate the potential use of emulsion electrospun fibers as drug carriers for local treatment of solid tumors.

Multiple release of polyplexes of plasmids VEGF and bFGF from electrospun fibrous scaffolds towards regeneration of mature blood vessels.

Key challenges associated with the outcomes of vascular grafting (for example, to fully vascularize engineered tissues and promptly regenerate blood vessel substitutes) remain unsolved. The local availability of angiogenic growth factors is highly desirable for tissue regeneration, and plasmid loading in scaffolds represents a powerful alternative for local production of tissue-inductive factors. No attempt has been made so far to clarify the efficacy of electrospun fibers with the loading of multiple plasmids to promote tissue regeneration. In the present study, core-sheath electrospun fibers with the encapsulation of polyplexes of basic fibroblast growth factor-encoding plasmid (pbFGF) and vascular endothelial growth factor-encoding plasmid (pVEGF) were evaluated to promote the generation of mature blood vessels. In vitro release indicated a sustained release of pDNA for ∼4 weeks with as low as ∼10% initial burst release, and the release patterns from the single and twofold plasmid-loaded systems coincided. In vitro investigations on human umbilical vein endothelial cells showed that the sustained release of pDNA from fibrous mats promoted cell attachment and viability, cell transfection and protein expression, and extracellular secretion of collagen IV and laminin. The acceleration of angiogenesis was assessed in vivo after subcutaneous implantation of fibrous scaffolds, and the explants were evaluated after 1, 2 and 4 weeks' treatment by histological and immunohistochemical staining. Compared with pDNA polyplex infiltrated fibrous mats, the pDNA polyplex encapsulated fibers alleviated the inflammation reaction and enhanced the generation of microvessels. Although there was no significant difference in the total number of microvessels, the density of mature vessels was significantly enhanced by the combined treatment with both pbFGF and pVEGF compared with those incorporating individual pDNA. The integration of the core-sheath structure, DNA condensation and multiple delivery strategies provided a potential platform for scaffold fabrication to regenerate functional tissues.

Release modulation and cytotoxicity of hydroxycamptothecin-loaded electrospun fibers with 2-hydroxypropyl-beta-cyclodextrin inoculations.

Hydroxycamptothecin (HCPT) is valid to various malignant tumors, but its insoluble and unstable lactone ring in physiological environment have restricted the clinic application. This work was aimed to formulate HCPT-loaded poly(DL-lactic acid)-poly(ethylene glycol) (PELA) fibrous mats through blend electrospinning with 2-hydroxypropyl-beta-cyclodextrin (HPCD) to modulate the drug release and matrix degradation, and to enhance the structural integrity and cytotoxicity of the released HCPT. The entire drug fraction retained its active lactone form within electrospun fibers, and that was maintained over 85% during incubation for over 1 month. A biphasic release pattern was determined for HCPT-loaded electrospun fibers, which can be modulated by the addition of HPCD. HPCD served as solubilizer to maintain a large concentration gradient for HCPT between saturation and diffusion, and liberated HPCD created microstructure of ultrafine fibers, leading a faster release profile in the second phase. In vitro cytotoxicity test showed over 7 times higher inhibitory activity against cancer cells for HCPT-loaded electrospun fibers than free drug during 72h incubation. Higher apoptosis rates and the arrest of the cell cycle during the S and G(2)/M phases were detected through flow cytometry analysis. It indicated therapeutic potentials of HCPT-loaded electrospun fibers as implantable anti-cancer agents for local chemotherapy.