Synthesis and Splice-Redirecting Activity of Branched, Arginine-Rich Peptide Dendrimer Conjugates of Peptide Nucleic Acid Oligonucleotides

Arginine-rich cell-penetrating peptides have found excellent utility in cell and in vivo models for enhancement of delivery of attached charge-neutral PNA or PMO oligonucleotides. We report the synthesis of dendrimeric peptides containing 2- or 4-branched arms each having one or more R-Ahx-R motifs and their disulfide conjugation to a PNA705 splice-redirecting oligonucleotide. Conjugates were assayed in a HeLa pLuc705 cell assay for luciferase up-regulation and splicing redirection. Whereas 8-Arg branched peptide−PNA conjugates showed poor activity compared to a linear (R-Ahx-R)4−PNA conjugate, 2-branched and some 4-branched 12 and 16 Arg peptide−PNA conjugates showed activity similar to that of the corresponding linear peptide−PNA conjugates. Many of the 12- and 16-Arg conjugates retained significant activity in the presence of serum. Evidence showed that biological activity in HeLa pLuc705 cells of the PNA conjugates of branched and linear (R-Ahx-R) peptides is associated with an energy-dependent uptake pathway, predominantly clathrin-dependent, but also with some caveolae dependence

Zwitterionic PEG-PC hydrogels modulate the foreign body response in a modulus-dependent manner

Reducing the foreign body response (FBR) to implanted biomaterials will enhance their performance in tissue engineering. Poly(ethylene glycol) (PEG) hydrogels are increasingly popular for this application due to their low cost, ease of use, and the ability to tune their compliance via molecular weight and crosslinking densities. PEG hydrogels can elicit chronic inflammation in vivo, but recent evidence has suggested that extremely hydrophilic, zwitterionic materials and particles can evade the immune system. To combine the advantages of PEG-based hydrogels with the hydrophilicity of zwitterions, we synthesized hydrogels with co-monomers PEG and the zwitterion phosphorylcholine (PC). Recent evidence suggests that stiff hydrogels elicit increased immune cell adhesion to hydrogels, which we attempted to reduce by increasing hydrogel hydrophilicity. Surprisingly, hydrogels with the highest amount of zwitterionic co-monomer elicited the highest FBR we observed. Lowering the hydrogel modulus (165 kPa to 3 kPa), or PC content (20 wt% to 0 wt%), mitigated this effect. A high density of macrophages was found at the surface of implants associated with a high FBR, and mass spectrometry analysis of the proteins adsorbed to these gels implicated extracellular matrix, immune response, and cell adhesion protein categories as drivers of macrophage recruitment to these hydrogels. Overall, we show that modulus regulates macrophage adhesion to zwitterionic-PEG hydrogels, and demonstrate that chemical modifications to hydrogels should be studied in parallel with their physical properties to optimize implant design

In vitro evaluation of electroporated gold nanoparticles and extremely-low frequency electromagnetic field anticancer activity against Hep-2 laryngeal cancer cells

Introduction. The extremely-low frequency electromagnetic field (ELFEMF) has been proposed for use in cancer therapy since it was found that magnetic waves interfere with many biological processes. Gold nanoparticles (Au-NPs) have been widely used for drug delivery during cancer in vitro studies due to their low cytotoxity and high biocompatibility. The electroporation of cancer cells in a presence of Au-NPs (EP Au-NPs) can induce cell apoptosis, alterations of cell cycle profile and morphological changes. The impact of ELFEMF and EP Au-NPs on morphology, cell cycle and activation of apoptosis-associated genes on Hep-2 laryngeal cancer cell line has not been studied yet. Materials and methods. ELFEMF on Hep-2 cells were carried out using four different conditions: 25/50 mT at 15/30 min, while Au-NPs were used as direct contact (DC) or with electroporation (EP, 10 pulses at 200V, equal time intervals of 4 sec). MTT assay was used to check the toxicity of DC Au-NPs. Expression of CASP3, P53, BAX and BCL2 genes was quantified using qPCR. Cell cycle was analyzed by flow cytometry. Hematoxylin and eosin (HE) staining was used to observe cell morphology. Results. Calculated IC50 of DC Au-NPs 24.36 μM (4.79 μg/ml) and such concentration was used for further DC and EP AuNPs experiments. The up-regulation of pro-apoptotic genes (CASP3, P53, BAX) and decreased expression of BCL2, respectively, was observed for all analyzed conditions with the highest differences for EP AuNPs and ELFEMF 50 mT/30 min in comparison to control cells. The highest content of cells arrested in G2/M phase was observed in ELFEMF-treated cells for 30 min both at 25 or 50 mT, while the cells treated with EP AuNPs or ELFEMF 50 mT/15 min showed highest ratios of apoptotic cells. HE staining of electroporated cells and cells exposed to ELFEMF’s low and higher frequencies for different times showed nuclear pleomorphic cells. Numerous apoptotic bodies were observed in the irregular cell membrane of neoplastic and necrotic cells with mixed euchromatin and heterochromatin. Conclusions. Our observations indicate that treatment of Hep-2 laryngeal cancer cells with ELFEMF for 30 min at 25–50 mT and EP Au-NPs can cause cell damage inducing apoptosis and cell cycle arrest

Combination antisense treatment for destructive exon skipping of myostatin and open reading frame rescue of dystrophin in neonatal <i>mdx</i> mice

The fatal X-linked Duchenne muscular dystrophy (DMD), characterized by progressive muscle wasting and muscle weakness, is caused by mutations within the DMD gene. The use of antisense oligonucleotides (AOs) modulating pre-mRNA splicing to restore the disrupted dystrophin reading frame, subsequently generating a shortened but functional protein has emerged as a potential strategy in DMD treatment. AO therapy has recently been applied to induce out-of-frame exon skipping of myostatin pre-mRNA, knocking-down expression of myostatin protein, and such an approach is suggested to enhance muscle hypertrophy/hyperplasia and to reduce muscle necrosis. Within this study, we investigated dual exon skipping of dystrophin and myostatin pre-mRNAs using phosphorodiamidate morpholino oligomers conjugated with an arginine-rich peptide (B-PMOs). Intraperitoneal administration of B-PMOs was performed in neonatal mdx males on the day of birth, and at weeks 3 and 6. At week 9, we observed in treated mice (as compared to age-matched, saline-injected controls) normalization of muscle mass, a recovery in dystrophin expression, and a decrease in muscle necrosis, particularly in the diaphragm. Our data provide a proof of concept for antisense therapy combining dystrophin restoration and myostatin inhibition for the treatment of DMD

Chlorhexidine versus Povidone-Iodine for the prevention of ‎Surgical Site ‎Infections: A review.‎

BackgroundSurgical Site Infections (SSIs) are the third most frequently reported health care-associated ‎infection‎ and it remain a major clinical problem despite improvements in prevention, as they ‎are associated with ‎significant mortality and morbidity. Prevention strategies for SSIs are based ‎on reducing the risk of infection by bacteria, So many antiseptic agents are ‎used, the most ‎common one are Chlorhexidine and Povidone-Iodine.‎AimsTo discuss the ‎findings of RCTs that compare Chlorhexidine versus Povidone-Iodine in the prevention of ‎Surgical ‎Site ‎Infections (SSIs).‎Methods This systematic review was carried out, including PubMed, Google Scholar, and EBSCO that ‎examining randomized trials of Chlorhexidine and Povidone-Iodine to summarize the major ‎RCT that compare Chlorhexidine versus Povidone-Iodine in the prevention of Surgical Site ‎Infections (SSIs).‎Results The review included six randomized studies that compare between Chlorhexidine and Povidone-‎Iodine for the prevention of SSIs. The findings showed that many studies prefer using ‎Chlorhexidine over Povidine-Iodine to reduce SSIs, few studies prefer using PVI as antiseptic ‎and other studies reported that there is no significant difference between both. ConclusionMajority of results prefer using Chlorhexidine than Povidone-Iodine‎ as antiseptics but ‎there were few findings prefer ‎PVI and other studies reported that there was no significant ‎difference between using them as ‎antiseptics.

Dystrophin regulates peripheral circadian SRF signalling

Dystrophin is a sarcolemmal protein essential for muscle contraction and maintenance, absence of which leads to the devastating muscle wasting disease Duchenne muscular dystrophy (DMD)[1, 2]. Dystrophin has an actin-binding domain [3–5], which specifically binds and stabilises filamentous (F)-actin[6], an integral component of the RhoA-actin-serum response factor (SRF)-pathway[7]. The RhoA-actin-SRF-pathway plays an essential role in circadian signalling whereby the hypothalamic suprachiasmatic nucleus, transmits systemic cues to peripheral tissues, activating SRF and transcription of clock target genes[8, 9]. Given dystrophin binds F-actin and disturbed SRF-signalling disrupts clock entrainment, we hypothesised that dystrophin loss causes circadian deficits. Here we show for the first time alterations in the RhoA-actin-SRF-signalling-pathway, in both dystrophin-deficient myotubes and dystrophic mouse models. Specifically, we demonstrate reduced F/G-actin ratios and nuclear MRTF, dysregulation of core clock and downstream target-genes, and down-regulation of key circadian genes in muscle biopsies from DMD patients harbouring an array of mutations. Further, disrupted circadian locomotor behaviour was observed in dystrophic mice indicative of disrupted SCN signalling, and indeed dystrophin protein was absent in the SCN of dystrophic animals. Dystrophin is thus a critically important component of the RhoA-actin-SRF-pathway and a novel mediator of circadian signalling in peripheral tissues, loss of which leads to circadian dysregulation

Global economic burden of unmet surgical need for appendicitis

Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112