Preparation, Characterization, and In Vitro Pharmacodynamics and Pharmacokinetics Evaluation of PEGylated Urolithin A Liposomes.

Urolithin A (Uro-A), a metabolite of ellagitannins in mammals' intestinal tract, displays broad biological properties in preclinical models, including anti-oxidant, anti-inflammatory, and anti-tumor effects. However, the clinical application of Uro-A is restricted because of its low aqueous solubility and short elimination half-life. Our purpose was to develop a delivery system to improve the bioavailability and anti-tumor efficacy of Uro-A. To achieve this goal, urolithin A-loaded PEGylated liposomes (Uro-A-PEG-LPs) were prepared for the first time and its physicochemical properties and anti-tumor efficacy in vitro were evaluated. The morphology of Uro-A-PEG-LPs displayed a uniform sphere under transmission electron microscope. The particle size, polydispersity index, zeta potential, and encapsulation efficiency of Uro-A-PEG-LPs were 122.8 ± 7.4 nm, 0.25 ± 0.16, - 25.5 ± 2.3 mV, and 94.6 ± 1.6%, respectively. Moreover, Uro-A-PEG-LPs possessed higher stability and could be stably stored at 4°C for a long time. In vitro release characteristics indicated that Uro-A-PEG-LPs possessed superior sustained release properties. The results of confocal laser scanning microscopy experiment showed that the coumarin 6-loaded PEGylated liposomes (C6-PEG-LPs) have superior cellular uptake than that of conventional liposomes. In addition, in vitro tests demonstrated that Uro-A-PEG-LPs elevated cytotoxicity and pro-apoptotic effect in human hepatoma cells comparing with free Uro-A. Furthermore, the results of pharmacokinetic experiments showed that the t1/2, AUC0-t, and MRT0-t of Uro-A-PEG-LPs increased to 4.58-fold, 2.33-fold, and 2.43-fold than those of free Uro-A solution, respectively. Collectively, these manifested that PEGylated liposomes might be a potential delivery system for Uro-A to prolonging in vivo circulation time, promoting cellular uptake, and enhancing its anti-tumor efficacy.

Insulin-like growth factor 1 can promote proliferation and osteogenic differentiation of human dental pulp stem cells via mTOR pathway.

Insulin-like growth factor 1 (IGF-1) is a multifunctional peptide that can enhance osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs). However, it remains unclear whether IGF-1 can promote osteogenic differentiation of human dental pulp stem cells (DPSCs). In our study, DPSCs were isolated from the impacted third molars, and treated with IGF-1. Osteogenic differentiation abilities were investigated. We found that IGF-1 activated the mTOR signaling pathway during osteogenic differentiation of DPSCs. IGF-1 also increased the expression of runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), osterix (OSX) and collagen type I (COL I) during this process. Rapamycin, an mTOR inhibitor, blocked osteogenic differentiation induced by IGF-1. Meanwhile, CCK-8 assay and flow cytometry results demonstrated that 10-200 ng/mL IGF-1 could enhance proliferation ability of DPSCs and 100 ng/mL was the optimal concentration. In summary, IGF-1 could promote proliferation and osteogenic differentiation of DPSCs via mTOR pathways, which might have clinical implications for osteoporosis.

Pathological and microbiological findings from mortality of the Chinese giant salamander (Andrias davidianus).

The Chinese giant salamander, Andrias davidianus, is a nationally protected and cultured species in China. Recently, a severe epizootic occurred in cultured Chinese giant salamanders in Hubei, Hunan, Sichuan, Shaanxi, and Zhejiang provinces of China, causing substantial economic losses. The typical clinical signs of diseased larval animals were jaw and abdominal swelling and subcutaneous hemorrhaging. Diseased adult animals exhibited skin hemorrhages, ulceration of the hind limbs, and multiple hemorrhagic spots in the visceral organs. Histopathological observation indicated tissue necrosis and cytoplasmic inclusions in the spleen, liver and kidney, suggestive of viral disease. A viral agent was isolated from affected tissues in cell culture. The virus was determined to be pathogenic after experimental infection. Electron microscopy revealed iridovirus-like virions with a size of 140-180 nm in diameter inside the kidney of naturally infected animals and in cell culture. The major capsid protein (MCP) of the virus exhibited 98-99 % sequence identity to ranaviruses. Additionally, phylogenetic analysis indicated that the virus belonged to the genus Ranavirus. Comparative analysis of the MCP gene sequence with those of other viruses previously isolated from Chinese giant salamanders revealed that these isolates were highly similar, although a few variations were observed. The virus was preliminarily named Chinese giant salamander iridovirus (GSIV).

Mandibuloacral dysplasia type A-associated progeria caused by homozygous LMNA mutation in a family from Southern China.

BACKGROUND: Mandibuloacral dysplasia type A (MADA) is a rare autosomal recessive disorder, characterized by growth retardation, skeletal abnormality with progressive osteolysis of the distal phalanges and clavicles, craniofacial anomalies with mandibular hypoplasia, lipodystrophy and mottled cutaneous pigmentation. Some patients may show progeroid features. MADA with partial lipodystrophy, more marked acral, can be caused by homozygous or compound heterozygous mutation in the gene encoding lamin A and lamin C (LMNA). MADA and Hutchinson-Gilford progeria syndrome are caused by the same gene and may represent a single disorder with varying degrees of severity. MAD patients characterized by generalized lipodystrophy (type B) affecting the face as well as extremities and severe progressive glomerulopathy present heterozygous compound mutations in the ZMPSTE24 gene. CASES PRESENTATIONS: We described a rare pedigree from Southern China, among them all three children presented with phenotypes of MADA associated progeria. The two elder sisters had developed severe mandibular hypoplasia associated progeria since the age of 1 year. The eldest sister showed a progressive osteolysis. The youngest son of 10 months showed severer lesions than those of his sisters at the same age, and presented possible muscle damage, and his symptoms progressed gradually. Three genes mutations including LMNA, ZMPSTE24 and BANF1 were tested in the family. LMNA gene sequencing revealed a homozygous missense mutation, c.1579C > T, p.R527C for all three siblings, and heterozygous mutations for their parents, whereas no mutations of ZMPSTE24 and BANF1 genes was detected among them. CONCLUSIONS: The same homozygous mutation of c.1579C > T of LMNA gene led to MADA associated progeria for the present family. The course of osteolysis for MADA is progressive.

[Identification of three novel frameshift mutations in the RUNX2 gene in three sporadic Chinese cases with cleidocranial dysplasia].

OBJECTIVE: To investigate the molecular etiology of three patients with sporadic cleidocranial dysplasia (CCD) and to provide genetic counseling and prenatal diagnosis for the family members based on the identified mutations. METHODS: Genomic DNA was extracted from peripheral blood samples using a standard method. All 7 coding exons of the RUNX2 gene and their flanking intronic sequences were amplified by PCR and sequenced directly. The PCR products of the exons with mutations from the three patients were cloned into a T-vector. Positive clones were sequenced. RESULTS: The three patients who have the typical CCD phenotypes involving clavicles, calvarium, stature, and teeth have carried various frameshift mutations in the RUNX2 gene. Patient 1 has a gross deletion of 80 nucleotides in exon 1 (c.227_306del), which caused a frameshift beginning at the Q/A repeat of the polypeptide and a premature termination (p.Ala76GlyfsX58). Patient 2 has a 2-bp duplication in exon 2 (c.471_472dupGG), which also caused a frameshift and a premature termination (p.Ala158GlyfsX19). Patient 3 has a T duplication in exon 7 (c.1321dupT), which caused a frameshift and a premature termination (p.Ser370PhefsX13) as well. CONCLUSION: The three novel mutations in RUNX2 are the underlying molecular mechanism for the CCD phenotypes of three sporadic Chinese patients, respectively. These have broadened the mutation spectrum of RUNX2 gene and provided a molecular basis for the genetic counseling and prenatal diagnosis for the affected families.

Coagulation/co-catalytic membrane integrated system for fouling-resistant and efficient water purification.

Low-pressure catalytic membranes allow efficient rejection of particulates and simultaneously removing organics pollutant in water, but the accumulation of dissolved organic matters (DOM) on membrane surface, which cover the catalytic sites and cause membrane fouling, challenges their stable operation in practical wastewater treatment. Here we propose a ferric salt-based coagulation/co-catalytic membrane integrated system that can effectively mitigate the detrimental effects of DOM. Ferric salt (Fe3+) serving both as a DOM coagulant to lower the membrane fouling and as a co-catalyst with the membrane-embedded MoS2 nanosheets to drive perxymonosulfate (PMS) activation and pollutant degradation. The membrane functionalized with 2H-phased MoS2 nanosheets showed improved hydrophilicity and fouling resistance relative to the blank polysulfone membrane. Attributed to the DOM coagulation and co-catalytic generation of surface-bound radicals for decontamination at membrane surface, the catalytic membrane/PMS/ Fe3+ system showed much less membrane fouling and 2.6 times higher pollutant degradation rate in wastewater treatment than the catalytic membrane alone. Our work imply a great potential of coagulation/co-catalytic membrane integrated system for water purification application.

[Effect of PEGylation of alpha-Momorcharin against its hepatotoxicity in rats].

OBJECTIVE: To explore the effect of PEGylation of alpha-Momorcharin (alpha-MMC), one of ribosome-inactivating proteins from bitter melon seed, against its hepatotoxicity in rats. METHODS: SD rats were randomized into NS group, alpha-MMC treated groups, and alpha-MMC-PEG treated groups. The doses of alpha-MMC and alpha-MMC-PEG were high, middle, and low dose (6.25, 2.08, 0.70 mg/kg). The rats were given different dose of alpha-MMC, or alpha-MMC-PEG via caudal vein every other day for consecutive 28 days and then left for 14 days recovery. The general condition of animals was observed, blood and liver samples were collected for liver function study and pathological examination on day 28 after initiation of administration and on day 14 after withdrawal. RESULTS: On day 28 after initiation of administration, the liver function damages were found in high-dose and middle-dose of alpha-MMC treated groups, such as the decreasing of ALB, increasing of GLB, A/G ratio decreasing and the dose-dependant increasing of AST, BIL and CHO. The pathological changes of hepatotoxicity were also observed in these two groups, including the massive hepatocyte, swelling degeneration, inflammatory cell infiltration, congestion and diffusive necrosis. However, the liver function and pathological changes in alpha-MMC-PEG treated groups were better than those in alpha-MMC treated groups. CONCLUSION: PEGylation could reduce the hepatotoxicity of alpha-MMC to rats.

The development and evaluation of hyaluronic acid coated mitochondrial targeting liposomes for celastrol delivery.

In order to precisely deliver celastrol into mitochondria of tumor cells, improve antitumor efficacy of celastrol and overcome its troublesome problems in clinical application, a novel multistage-targeted celastrol delivery system (C-TL/HA) was developed via electrostatic binding of hyaluronic acid (HA) to celastrol-loaded cationic liposomes composed of natural soybean phosphatidylcholine and cholesterol modified with mitochondrial targeting molecular TPP. Study results in this article showed that C-TL/HA successfully transported celastrol into mitochondria, effectively activated apoptosis of mitochondrial pathway, exerted higher tumor inhibition efficiency and lower toxic side effects compared with free celastrol. More importantly, HA coating not only enabled this delivery system to have good stability and safety in vivo, but also increased drug uptake and facilitated tumor targeting through recognizing CD44 receptors rich on the surface of tumor cells. Conclusively, this HA-coated mitochondrial targeting liposomes may provide a prospect for the clinical application of celastrol in tumor therapy.

Formulation and evaluation of a two-stage targeted liposome coated with hyaluronic acid for improving lung cancer chemotherapy and overcoming multidrug resistance.

Multidrug resistance (MDR) has emerged as a prominent challenge contributing to the ineffectiveness of chemotherapy in treating non-small cell lung cancer (NSCLC) patients. Currently, mitochondria of cancer cells are identified as a promising target for overcoming MDR due to their crucial role in intrinsic apoptosis pathway and energy supply centers. Here, a two-stage targeted liposome (HA/TT LP/PTX) was successfully developed via a two-step process: PTX-loaded cationic liposome (TT LP/PTX) were formulated by lipid film hydration & ultrasound technique, followed by further coating with natural anionic polysaccharide hyaluronic acid (HA). TT, an amphipathic polymer conjugate of triphenylphosphine (TPP)-tocopheryl polyethylene glycol succinate (TPGS), was used to modify the liposomes for mitochondrial targeting. The average particle size, zeta potential and encapsulation efficiency (EE%) of HA/TT LP/PTX were found to be 153 nm, -30.3 mV and 92.1% based on the optimal prescription of HA/TT LP/PTX. Compared to cationic liposome, HA-coated liposomes showed improved stability and safety, including biological stability in serum, cytocompatibility, and lower hemolysis percentage. In drug-resistant A549/T cells, HA was shown to improve the cellular uptake of PTX through CD44 receptor-mediated endocytosis and subsequent degradation by hyaluronidase (HAase) in endosomes. Following this, the exposure of TT polymer facilitated the accumulation of PTX within the mitochondria. As a result, the function of mitochondria in A549/T cells was disturbed, leading to an increased ROS level, decreased ATP level, dissipated MMP, and increased G2/M phase arrest. This resulted in a higher apoptotic rate and stronger anticancer efficacy.

Biomechanical and histomorphological analysis of the mandible in rats with chronic kidney disease.

The present study aimed to investigate the biomechanical and histomorphological features of mandibles in an adenine-induced chronic kidney disease-mineral and bone disorder (CKD-MBD) rat model of CKD. A total of 14 Sprague-Dawley rats were randomized into the following two groups: control group and CKD group. At the end of the sixth week, all rats were euthanized, and serum was collected for biochemical marker tests. Macroscopic bone growth and biomechanical parameters were measured in the right hemimandible, while the left hemimandible was used for bone histomorphometric analysis. Compared to the control group, the CKD group showed a significant increase in serum creatinine, blood urea nitrogen, and serum parathyroid hormone at the end of the sixth week. The biomechanical structural properties significantly decreased in the CKD group compared to the control group. Bone histomorphometric analysis indicated that the trabecular bone volume of rats in the CKD group was significantly lower than that of the control group. In the CKD groups, the bone formation parameters of the trabecular bone were significantly increased, while the bone mineralization apposition rates of both the trabecular bone and periosteal cortical bone were significantly increased. The rat CKD model showed deteriorated structural mechanics, low trabecular bone volume, high trabecular bone formation, increased trabecular bone mineralization apposition rate, and increased cortical bone mineralization apposition rate, which met the characteristics of osteitis fibrosa, indicating that this model is a useful tool for the study of mandible diseases in CKD patients.

PEGylation is effective in reducing immunogenicity, immunotoxicity, and hepatotoxicity of α-momorcharin in vivo.

BACKGROUND AND AIM: α-momorcharin (α-MMC), a type I ribosome-inactivating protein (RIP) from Momordica charantia, is well known for its antitumor and antivirus activities. However, the immunotoxicity and hepatotoxicity hampers its potential therapeutic usage. In order to reduce its toxicity, we had modified the α-MMC with polyethylene glycol (PEG), and detected the toxicity of the PEGylated α-MMC conjugates (α-MMC-PEG) in vivo. MATERIALS AND METHODS: After α-MMC purified from bitter melon seeds, α-MMC-PEG was constructed with a branched 20 kDa (mPEG) 2-Lys-NHS, the tests of immunogenicity, immunotoxicity, and general toxicity of α-MMC-PEG were conducted in guinea pig and rat. RESULTS: The titer of specific IgG in rats, immunized by α-MMC-PEG, were approximately one-third of those that by α-MMC, all the guinea pigs treated with α-MMC died of anaphylaxis shock within 5 min, while no animals treated with α-MMC-PEG died in the active systemic anaphylaxis (ASA) test. The passive cutaneous anaphylaxis (PCA) reaction of α-MMC-PEG challenge in rats was significantly smaller than that of the α-MMC. The liver damage was greatly released, such as the change of globulin (GLB), aspartate aminotransferase (AST), total bilirubin (TBIL) cholesterol (CHOL), albumin (ALB), and the degree of hepatocyte necrosis in repeated toxicity study. CONCLUSIONS: PEGylation is effective in reducing the immunogenicity, immunotoxicity, and hepatotoxicity of α-MMC in vivo.

Genome sequencing identified a novel exonic microdeletion in the RUNX2 gene that causes cleidocranial dysplasia.

BACKGROUND AND AIMS: Cleidocranial dysplasia (CCD) represents a rare autosomal dominant skeletal dysplasia caused by mutations that induce haploinsufficiency in RUNX2, the important transcription factor of osteoblasts related to bone/cartilage development and maintenance. Clavicular hypoplasia, which involves aberrant tooth/craniofacial bone/skeletal formation, is a feature of classic CCD. RUNX2 mutations can be found in approximately 60-70% of patients with CCD, and around ∼10% of these mutations are microdeletions. The present paper describes the radiological and clinical characteristics of a 5-year-old girl who showed representative CCD features, including extra teeth, aplasia of clavicles, sloping shoulders, marked calvarial hypomineralization, and osteoporosis. MATERIALS AND METHODS: We obtained genomic DNA of her family members and performed whole-genome sequencing (WGS) for samples collected from the proband. Quantitative fluorescent PCR (QF-PCR) and specific PCR plus electrophoresis were then performed as validation assays for all participants. In vitro analysis was performed. Luciferase assay for Runx2 transcription activity and evaluation of mRNA levels of Runx2 downstream osteogenic markers were conducted. RESULTS: WGS identified a 11.38-kb microdeletion in RUNX2 comprising 8-9 exons, which was validated by QF-PCR and specific PCR plus electrophoresis. In vitro experiments confirmed the pathogenicity of this variation. CONCLUSION: The present study identified a 11.38-kb microdeletion in RUNX2 that causes CCD. The deletion in the PST domain of RUNX2 reduces its transcription activity and reduces osteogenic marker levels, eventually decreasing the differentiation of osteoblasts. These findings clarify the role of the CCD-related mechanism in the development of CCD and suggest that it is important to consider copy number variation for the suspected familial patients early.

The oral bioaccessibility and gingival cytotoxicity of metal(loid)s in wild vegetables from mining areas: Implication for human oral health.

Background: Heavy metal(loid)s are frequently detected in vegetables posing potential human health risks, especially for those grown around mining areas. However, the oral bioaccessibility and gingival cytotoxicity of heavy metals in wild vegetables remain unclear. Methods: In this study, we assessed the total and bioaccessible Cr, As, Cd, Pb, and Ni in four wild vegetables from mining areas in Southwest China. In addition, the cytotoxicity and underlying mechanisms of vegetable saliva extracts on human gingival epithelial cells (HGEC) were studied. Results: The Plantago asiatica L. (PAL) showed the highest bioaccessible Cr, As, Cd, and Pb, while the greatest bioaccessible Ni was in Taraxacum mongolicum (TMM). The Pteridium aquilinum (PAM), Chenopodium album L. (CAL), and TMM extracts decreased cell viability, induced apoptosis, caused DNA damage, and disrupted associated gene expressions. However, PAL extracts which have the highest bioaccessible heavy metals did not present adverse effects on HGEC, which may be due to its inhibition of apoptosis by upregulating p53 and Bcl-2. Conclusion: Our results indicated that polluted vegetable intake caused toxic effects on human gingiva. The heavy metals in vegetables were not positively related to human health risks. Collectively, both bioaccessibility and toxic data should be considered for accurate risk assessment.

Application Effect of Computer-Assisted Local Anesthesia in Patient Operation.

In order to avoid the psychological harm caused by pain to patients, in this study, the application effect of computer-assisted local anesthesia in patient surgery was studied. In this method, 72 patients with hypertension, 35 males and 37 females, aged 53-83 years, with an average age of 70.8 ± 1.3 years, were selected for appointment tooth extraction in the department of stomatology from January to December 2014. All patients were booked for tooth extraction by ECG monitoring. Patients who were contraindicated for tooth extraction, had a history of mental illness, and had used antianxiety drugs and sedatives within 1 week before surgery were excluded. Patients were randomly divided into two groups according to their ID numbers: observation group, 36 cases, and control group. Painless oral local anesthesia injection instrument was used for local anesthesia injection. In the control group, 36 patients were injected with local anesthesia by traditional manual injection. The results showed that 86.11% of patients in the observation group had decreased anxiety scores after anesthesia, while only 13.88% of patients in the control group had decreased anxiety scores. Among patients with decreased anxiety scores, 80.65% in the observation group became nondental anxiety compared with 28.57% in the control group. Computer-assisted oral local anesthesia can effectively control dental anxiety and relieve the pain and discomfort of local anesthesia injection, and improve patient satisfaction, conducive to the smooth nursing work.

[Preparation of zoledronic-acid-loaded collagen membrane].

OBJECTIVE: To develop a new local delivery system, osteoclastic-inhibitor-loaded collagen membrane, and to evaluate its drug loading and drug release properties. METHODS: Efforts were made to develop the drug-loaded membranes by combining two commercially available collagen barrier membranes (Bio-Gide and BME-10X) with zoledronic acid (ZA). The physicochemical and pharmacological properties of resulting materials were determined using SEM, EDS, FTIR, and HPLC. RESULTS: After ZA loading, the micropores between the thin collagen fibers in the Bio-Gide disappeared, whereas crystalloid powders appeared on the surface of pore walls in BME-10X. Phosphorus was detected on both drug-loaded membranes. The Amides shifted. With the same drug solution, Bio-Gide presented larger amount of ZA loading and slower ZA release than BME-10X. ZA loading did not affect the 3D fiber network and the degradation of membranes. CONCLUSION: Both collagen membranes load ZA successfully and delay drug release. But Bio-Gide shows higher loading values and slower release than BME-10X.

Mucopolysaccharidosis III in Mainland China: natural history, clinical and molecular characteristics of 34 patients.

Objectives Sanfilippo syndrome (Mucopolysaccharidosis III, MPS III) is a rare autosomal recessive hereditary disease, which is caused by lysosomal enzyme deficiency. This study was operated to investigate clinical and molecular characteristics of patients with MPS III, which will improve the diagnosis and treatment of MPS III. Method Thirty four patients with MPS III were assessed using clinical evaluation, questionnaire, and scoring system. Results Among the 34 patients, 14 had MPS IIIA, 19 had MPS III B, and one had MPS III C. Speech delay (100%) and intellectual disability (100%) were the most prevalent clinical manifestations in this cohort, followed by hyperactivity (94.12%), hirsutism (91.18%), enlarged head circumference (73.52%), repeated diarrhea (67.64%), sparse teeth (67.64%), and Mongolian spots (64.71%). There were two clinical manifestations that were significantly different between IIIA and IIIB: Hepatosplenomegaly and serrated teeth. The most common initial symptoms at diagnosis were speech delay (52.94%), hyperactivity (35.29%), and mental retardation (29.41%). Genetic analysis of 25 patients was conducted, which identified 12 novel mutations. Conclusion When language retardation, mental retardation, and rough facial features occurred, MPS III should be considered. At same time, more examination should be operated, such as examination of changes in cranial magnetic resonance imaging of cerebral cortex atrophy. Hepatosplenomegaly and serrated teeth could be used clinically to preliminarily distinguish IIIA from IIIB.

[Research progresses on electroactive and electrically conductive polymers for tissue engineering scaffolds].

Electroactive and/or electrically conductive polymers have shown potential applications in the culture of excitable cells and as the electroactive scaffolds for neuronal or cardiac tissue engineering. The biocompatibility of the conductive polymer can be improved by covalently grafting or blending with oligo- or polypeptides. The new progresses in this area on two types of conductive polymers, polypyrrole and polyaniline (PANi) are reviewed in this paper. The studies of oligopeptide-modified PANi and electrospun PANi/gelatin nanofibers are highlighted.

New devices and techniques for endoscopic closure of gastrointestinal perforations.

Gastrointestinal perforations, which need to be managed quickly, are associated with high morbidity and mortality. Treatments used to close these perforations range from surgery to endoscopic therapy. Nowadays, with the development of new devices and techniques, endoscopic therapy is becoming more popular. However, there are different indications and clinical efficacies between different methods, because of the diverse properties of endoscopic devices and techniques. Successful management also depends on other factors, such as the precise location of the perforation, its size and the length of time between the occurrence and diagnosis. In this study, we performed a comprehensive review of various devices and introduced the different techniques that are considered effective to treat gastrointestinal perforations. In addition, we focused on the different methods used to achieve successful closure, based on the literature and our clinical experiences.

Plasmid-Based Stat3 siRNA Delivered by Functional Graphene Oxide Suppresses Mouse Malignant Melanoma Cell Growth.

RNA interference (RNAi) has been used for cancer gene therapy in recent years. However, the application of RNAi is hindered in the absence of safe and efficient gene delivery. In this article, a novel vehicle of graphene oxide functionalized with polyethylenimine and polyethylene glycol (GO-PEI-PEG) was successfully synthetized and then used to deliver plasmid-based Stat3 siRNA. The carrier can readily bind plasmid with high transfection efficiency. Moreover, molecular biology studies reveal that Stat3-related gene and protein expressions were significantly inhibited, suggesting that the formation of GO-PEI-PEG complexes could be utilized as a promising gene delivery in cancer therapy.

PEGylation alleviates the non-specific toxicities of Alpha-Momorcharin and preserves its antitumor efficacy in vivo.

Alpha-Momorcharin (α-MMC) is a ribosome inactivating protein from Momordica charantia with anti-tumor activity. Previously, we had observed that modification of α-MMC with polyethylene glycol (PEG) could reduce toxicity, but it also reduces its anti-tumor activity in vitro. This study aims to investigate whether the metabolism-extended properties of α-MMC resulting from PEGylation could preserve its anti-tumor efficacy in vivo through pharmacokinetics and antitumor experiments. The pharmacokinetics experiments were conducted in rats using the TCA (Trichloroacetic Acid) method. Antitumor activity in vivo was investigated in murine mammary carcinoma (EMT-6) and human mammary carcinoma (MDA-MB-231) transplanted tumor mouse models. The results showed that PEGylation increased the plasma half-life of α-MMC in rats from 6.2-7.5 h to 52-87 h. When administered at 1 mg/kg, α-MMC-PEG and α-MMC showed similar anti-tumor activities in vivo, with a T/C% of 38.56% for α-MMC versus 35.43% for α-MMC-PEG in the EMT-6 tumor model and 36.30% for α-MMC versus 39.88% for α-MMC-PEG in the MDA-MB-231 tumor model (p > 0.05). Importantly, at the dose of 3 mg/kg, all the animals treated with α-MMC died while the animals treated with α-MMC-PEG exhibited only moderate toxic reactions, and α-MMC-PEG exhibited improved anti-tumor efficacy with a T/C% (relative tumor growth rate) of 25.18% and 21.07% in the EMT-6 and MDA-MB-231 tumor models, respectively. The present study demonstrates that PEGylation extends the half-life of α-MMC and alleviates non-specific toxicity, thereby preserving its antitumor efficacy in vivo, and a higher lever of dosage can be used to achieve better therapeutic efficacy.