Embedding Peptides into Synthetic Polymers: Radical Ring-Opening Copolymerization of Cyclic Peptides.

Biopolymers such as proteins and nucleic acids are the key building blocks of life. Synthetic polymers have nevertheless revolutionized our everyday life through their robust synthetic accessibility. Combining the unmatched functionality of biopolymers with the robustness of tailorable synthetic polymers holds the promise to create materials that can be designed ad hoc for a wide array of applications. Radical polymerization is the most widely applied polymerization technique in both fundamental science and industrial polymer production. While this polymerization technique is robust and well controlled, it generally yields unfunctional all-carbon backbones. Combinations of natural polymers such as peptides, with synthetic polymers, are thus limited to tethering peptides onto the side chains or chain ends of the latter. This synthetic limitation is a critical restraint, considering that the function of biopolymers is programmed into the sequence of their main chain (i.e., primary structure). Here, we report the radical copolymerization of peptides and synthetic comonomers yielding synthetic polymers with defined peptide sequences embedded into their main chain. Key was the development of a solid-phase peptide synthesis (SPPS) approach to generate synthetic access to peptide conjugates containing allylic sulfides. Following cyclization, the obtained peptide monomers can be readily copolymerized with N,N-dimethylacrylamide (DMA)─controlled by reversible addition-fragmentation chain transfer (RAFT). Importantly, the developed synthetic strategy is compatible with all 20 standard amino acids and uses exclusively standard SPPS chemicals or chemicals accessible in one-step synthesis─prerequisite for widespread and universal application.

Hybrid Nanoparticle for Co-delivering Paclitaxel and Dihydroartemisinin to Exhibit Synergic Anticancer Therapeutics.

AIM: Anticancer treatment is required to provide effective and safe patient medicines. This research aided in developing and applying nanoparticles (NPs) for cancer treatment. BACKGROUND: The poor solubility of paclitaxel (PTX) restricts its therapeutic efficacy because of allergic side effects caused by formulation excipients. To overcome this, PTX was coupled with artemisinin derivatives and loaded into an NP drug delivery system to enhance its effects while addressing its low solubility. OBJECTIVES: This study prepared and characterized a hybrid PLGA-lecithin NP containing dihydroartemisinin (DHA) and PTX for synergic anticancer therapy. A lyophilization study improved the stability of the NP drug formulations. METHODS: Dual PTX- and DHA-loaded PLGA- and lecithin-based NPs were prepared using a single-step solvent evaporation method. The NP suspensions were lyophilized, and the types and ratios of cryoprotectants were investigated. The physicochemical properties of NPs and lyophilized cakes (Lyo-NPs) were characterized. The stability of the Lyo-NPs was investigated at 2-8°C and room conditions. The anticancer effects of the drug combination, NP suspension, and lyophilized powder were analyzed using an in vitro cytotoxicity assay and an in vivo model. RESULTS: The optimal PTX-DHA loaded PLGA-lecithin-NP was formulated (200 nm, PDI: 0.248 ± 0.003, Zeta potential: -33.60 ± 3.39 mV). Mannitol was selected for lyophilization. Lyo-NPs improved the stability of the NPs (1 year), wherein the physicochemical properties of the NPs were maintained (RDI was close to 1.0). An in-vitro cytotoxicity assay of PTX combined with DHA showed a synergistic anticancer effect (CI <1.0). The suppressive effects of Lyo-NPs on tumor growth in vivo were dose-dependent. While the cocktail of free drugs showed high toxicity (7.5 mg PTX-15 mg DHA/kg) in-vivo, Lyo-NPs showed no statistical differences in hematological and biochemical parameters compared to the control. CONCLUSION: Dual-drug-loaded hybrid PLGA-lecithin NP is a potential system to minimize severe side effects while enhancing antitumor efficacy, in which lyophilization is a key process to increase stability.

Bacopa monnieri ameliorates memory deficits in olfactory bulbectomized mice: possible involvement of glutamatergic and cholinergic systems.

This study investigated the effects of alcoholic extract of Bacopa monnieri (L.) Wettst. (BM) on cognitive deficits using olfactory bulbectomized (OBX) mice and the underlying molecular mechanisms of its action. OBX mice were treated daily with BM (50 mg/kg, p.o.) or a reference drug, tacrine (2.5 mg/kg, i.p.), 1 week before and continuously 3 days after OBX. Cognitive performance of the animals was analyzed by the novel object recognition test, modified Y maze test, and fear conditioning test. Brain tissues of OBX animals were used for neurochemical and immunohistochemical studies. OBX impaired non-spatial short-term memory, spatial working memory, and long-term fair memory. BM administration ameliorated these memory disturbances. The effect of BM on short-term memory deficits was abolished by a muscarinic receptor antagonist, scopolamine. OBX downregulated phosphorylation of synaptic plasticity-related signaling proteins: NR1 subunit of N-methyl-D-aspartate receptor, glutamate receptor 1 (GluR1), and calmodulin-dependent kinase II but not cyclic AMP-responsive element binding protein (CREB), and reduced brain-derived neurotrophic factor (BDNF) mRNA in the hippocampus. OBX also reduced choline acetyltransferase in the hippocampus and cholinergic neurons in the medial septum, and enlarged the size of lateral ventricle. BM administration reversed these OBX-induced neurochemical and histological alterations, except the decrease of GluR1 phosphorylation, and enhanced CREB phosphorylation. Moreover, BM treatment inhibited ex vivo activity of acetylcholinesterase in the brain. These results indicate that BM treatment ameliorates OBX-induced cognition dysfunction via a mechanism involving enhancement of synaptic plasticity-related signaling and BDNF transcription and protection of cholinergic systems from OBX-induced neuronal damage.

Effects of Extracellular Vesicles Secreted by TGFß-Stimulated Umbilical Cord Mesenchymal Stem Cells on Skin Fibroblasts by Promoting Fibroblast Migration and ECM Protein Production.

Umbilical cord-derived mesenchymal stem cells (UCMSCs) have been illustrated for their roles in immunological modulation and tissue regeneration through the secretome. Additionally, culture conditions can trigger the secretion of extracellular vesicles (EVs) into extracellular environments with significant bioactivities. This study aims to investigate the roles of three EV sub-populations released by UCMSCs primed with transforming growth factor ß (TGFß) and their capacity to alter dermal fibroblast functions for skin aging. Results show that three EV sub-populations, including apoptotic bodies (ABs), microvesicles (MVs), and exosomes (EXs), were separated from conditioned media. These three EVs carried growth factors, such as FGF-2, HGF, and VEGF-A, and did not express noticeable effects on fibroblast proliferation and migration. Only EX from TGFß-stimulated UCMSCs exhibited a better capacity to promote fibroblasts migrating to close scratched wounds than EX from UCMSCs cultured in the normal condition from 24 h to 52 h. Additionally, mRNA levels of ECM genes (COL I, COL III, Elastin, HAS II, and HAS III) were detected with lower levels in fibroblasts treated with EVs from normal UCMSCs or TGFß-stimulated UCMSCs compared to EV-depleted condition. On the contrary, the protein levels of total collagen and elastin released by fibroblasts were greater in the cell groups treated with EVs compared to EV-depleted conditions; particularly elastin associated with TGFß-stimulated UCMSCs. These data indicate the potential roles of EVs from UCMSCs in protecting skin from aging by promoting ECM protein production.

Optimization of human umbilical cord blood-derived mesenchymal stem cell isolation and culture methods in serum- and xeno-free conditions.

BACKGROUND: Although umbilical cord blood (UCB) is identified as a source of mesenchymal stem cells (MSCs) with various advantages, the success in cell isolation is volatile. Therefore, it is necessary to optimize methods of cord blood-derived MSC (UCB-MSC) isolation and culture. In this study, we evaluated the efficiency of UCB-MSC isolation and expansion using different commercially available serum- and xeno-free media and investigated the capacity of autologous serum and plasma as a supplement to support cell proliferation. Additionally, we defined the presence of multilineage-differentiating stress-enduring (Muse) cells in the UCB-MSC population. Functions of UCB-MSC in in vitro angiogenesis processes and anti-cancer were also verified. METHODS: Mononuclear cells were isolated using density gradient separation and cultured in four commercial media kits, as well as four surface coating solutions. UCB-MSCs were characterized and tested on tube formation assay, and co-cultured with SK-MEL cells in a transwell system. RESULTS: The results showed that only StemMACS™ MSC Expansion Media is more appropriate to isolate and culture UCB-MSCs. The cells exhibited a high cell proliferation rate, CFU forming capability, MSC surface marker expression, trilineage differentiate potential, and chromosome stability. In addition, the culture conditions with autologous serum coating and autologous plasma supplement enhanced cell growth and colony forming. This cell population contained Muse cells at rate of 0.3%. Moreover, UCB-MSCs could induce the tube formation of human umbilical vein endothelial cells and inhibit more than 50% of SK-MEL cell growth. CONCLUSIONS: UCB-MSCs could be high-yield isolated and expanded under serum- and xeno-free conditions by using the StemMACS™ MSC Expansion Media kit. Autologous serum coating and plasma supplement enhanced cell proliferation. These UCB-MSCs had effected the tube formation process and an anti-cancer impact.

Emergency surgery for obstructed colorectal cancer in Vietnam.

BACKGROUND: The benefit of one-stage surgery in emergency surgery for obstructing colorectal cancer (oCRC) by colorectal surgeons has increased during the last century but little is known about the outcomes of this technique conducted by general surgeons in developing countries. This retrospective study was to evaluate the outcomes of emergency surgery for oCRC in a general surgery unit. METHODS: A retrospective review of data from 1175 patients who underwent colorectal surgery between January 2013 and January 2018 was performed. Among these, a total of 186 patients with oCRC who underwent surgery within 24 h of hospital admission were analyzed. For patients with resectable right-sided oCRC, one-stage surgery was performed. For left-sided oCRC, primary anastomosis was mainly attempted; otherwise, a stoma was formed. The rates of primary resection, PRa, stoma, mortality, and morbidity were evaluated. RESULTS: Among 186 patients, oCRC involving the right colon, left colon, and rectum were found in 33.3%, 59.1% and 7.5% respectively. Primary resection and anastomosis were performed in 100%, 44.7%, and 0% of patients with oCRC in the right colon, left colon, and rectum respectively. The complication incidence based on Clavien-Dindo grade III or higher was 16.1% and the mortality rate was 7.5%. The median length of hospital stay was 8.5 days, ranging from 2 to 70 days. CONCLUSION: General surgeons with colorectal surgery experience can still manage oCRC effectively. Primary resection and anastomosis for left-sided oCRC is safe in selective patients. The emergency surgery for oCRC could be benefit with the participation of colorectal surgeons.

Differential Wound Healing Capacity of Mesenchymal Stem Cell-Derived Exosomes Originated From Bone Marrow, Adipose Tissue and Umbilical Cord Under Serum- and Xeno-Free Condition.

Exosomes are nano-scale and closed membrane vesicles which are promising for therapeutic applications due to exosome-enclosed therapeutic molecules such as DNA, small RNAs, proteins and lipids. Recently, it has been demonstrated that mesenchymal stem cell (MSC)-derived exosomes have capacity to regulate many biological events associated with wound healing process, such as cell proliferation, cell migration and blood vessel formation. This study investigated the regenerative potentials for cutaneous tissue, in regard to growth factors associated with wound healing and skin cell proliferation and migration, by exosomes released from primary MSCs originated from bone marrow (BM), adipose tissue (AD), and umbilical cord (UC) under serum- and xeno-free condition. We found crucial wound healing-mediated growth factors, such as vascular endothelial growth factor A (VEGF-A), fibroblast growth factor 2 (FGF-2), hepatocyte growth factor (HGF), and platelet-derived growth factor BB (PDGF-BB) in exosomes derived from all three MSC sources. However, expression levels of these growth factors in exosomes were influenced by MSC origins, especially transforming growth factor beta (TGF-ß) was only detected in UCMSC-derived exosomes. All exosomes released by three MSCs sources induced keratinocyte and fibroblast proliferation and migration; and, the induction of cell migration is a dependent manner with the higher dose of exosomes was used (20 µg), the faster migration rate was observed. Additionally, the influences of exosomes on cell proliferation and migration was associated with exosome origins and also target cells of exosomes that the greatest induction of primary dermal fibroblasts belongs to BMMSC-derived exosomes and keratinocytes belongs to UCMSC-derived exosomes. Data from this study indicated that BMMSCs and UCMSCs under clinical condition secreted exosomes are promising to develop into therapeutic products for wound healing treatment.

Phytochemical investigation on Vitex negundo leaves and their anti-inflammatory and analgesic activities

Abstract The phytochemical investigation on Vitex negundo leaves has led to the isolation of one new iridoid glucoside (8α-hydroxy-4-carboxyl-5ßH-9ßH-iridoid-1α-O-(6'-O-(6,7-dihydrofoliamenthonyl)-ß-ᴅ-glucopyranoside, 3), together with three known compounds, namely agnuside (1), 6'-O-E-caffeoylmussaenosidic acid (2), and 3,5-dicaffeoylquinic acid (4). The HPLC analytical study was also performed to quantify the content of agnuside (1) in dried leaves. The results indicated the very high content of 1 (3.04 ± 0.02%). The method was also validated by various parameters, including linearity (R2= 0.9999), precision (intra-day RSD ≤ 2.50%, inter-day RSD= 0.76%), and accuracy (recovery rates 96.58-101.86%). The animal testing data showed that the extract did not reduce pain at the doses of 9.6 and 28.8 g /kg (leaf weight/body weight) in the hot plates and pain measuring models but showed the pain reduction in the acetic acid-induced pain model. The extract at the dose of 5.6 g/kg (leaf weight/body weight) also had effects on the acute inflammation in the carrageenin-induced edema model. The extract at the dose 9.6 and 28.8 g/kg (leaf weight/body weight) also showed significant chronic anti-inflammation, comparable to methylprednisolone at the dose 10 mg/kg on the mouse peritoneal