Multi-sensitive functionalized niosomal nanocarriers for controllable gene delivery in vitro and in vivo

MicroRNAs, which can contribute to numerous cellular functions through post-transcriptional silencing, have become well-documented candidates for cancer treatment applications, particularly in chemo-resistant cancers. Herein, several formulations were examined to optimize the essential parameters, and the niosomal formulation consisting of cholesterol:tween-80:DOTAP:PEG with 9:69:15:7 ratio had the best physicochemical parameters including spherical shape, high entrapment efficiency, small diameter (81 ± 0.65 nm), and appropriate positive charge (23 ± 0.64 mV). Here, we aimed to design a system with increased delivery efficiency which was tested by the encapsulation of miR-34a within niosome NPs and assessed the nano-niosomal delivery of miR-34a as a tumor suppressor in MCF-7 human adenocarcinoma cells. The results showed that our novel niosome systems with non-ionic surfactants can successfully eliminate cancer cells by increasing the expression of p53 and reducing the expression of NF-κB. In comparison with the free dispersion of miR-34a, the lysis of a nano-sized delivery system demonstrated a better cytotoxicity effect against cancer cells. Similar results were obtained by performing in vivo test on the 4T1 xenografted Balb/C mouse tumor model and the miR-34a-loaded niosomes displayed a better reduction in tumor size by improving approximately + 13% in tumor inhabitation rate while maintaining the bodyweight close to the first day. Therefore, it is concluded that miR-34a delivery via niosomes has high potential as a tumor suppressor and a reliable procedure for breast cancer treatment.

Graphical Abstract

Graphene-based nanomaterials for stimuli-sensitive controlled delivery of therapeutic molecules

Stimuli-responsive drug delivery has attracted tremendous attention in the past decades. It provides a spatial- and temporal-controlled release in response to different triggers, thus enabling highly efficient drug delivery and minimizing drug side effects. Graphene-based nanomaterials have been broadly explored, and they show great potential in smart drug delivery due to their stimuli-responsive behavior and high loading capacity for an extended range of drug molecules. These characteristics are a result of high surface area, mechanical stability and chemical stability, and excellent optical, electrical, and thermal properties. Their great and infinite functionalization potential also allows them to be integrated into several types of polymers, macromolecules, or other nanoparticles, leading to the fabrication of novel nanocarriers with enhanced biocompatibility and trigger-sensitive properties. Thus, numerous studies have been dedicated to graphene modification and functionalization. In the current review, we introduce graphene derivatives and different graphene-based nanomaterials utilized in drug delivery and discuss the most important advances in their functionalization and modification. Also, their potential and progress in an intelligent drug release in response to different types of stimuli either endogenous (pH, redox conditions, and reactive oxygen species (ROS)) or exogenous (temperature, near-infrared (NIR) radiation, and electric field) will be debated.

Stimuli-responsive injectable chitosan-based hydrogels for controlled drug delivery systems

In the last decade, injectable hydrogels have attracted a lot of attention due to their excellent functional properties in the field of drug delivery for precise, non-invasive and focused tissue locations. Therefore, designing drug delivery systems (DDS) responsive to hydrogel stimuli to release a drug to an external stimulus with various advantages, can be very challenging. Due to their biocompatibility, mucosal adhesion, and hemostatic activity, chitosan (Chitosan)-based hydrogels offer a lot of potential for tissue engineering and drug delivery. It can be difficult to manage the structure of these stimuli-responsive CS hydrogels or they may require additional crosslinking agents, such as hydrogels with dual pH and thermo-responsiveness. Therefore, it is crucial to create these hydrogels for medicinal applications.

Smart stimuli-responsive injectable gels and hydrogels for drug delivery and tissue engineering applications: A review

Hydrogels are widely used biomaterials in the delivery of therapeutic agents, including drugs, genes, proteins, etc., as well as tissue engineering, due to obvious properties such as biocompatibility and their similarity to natural body tissues. Some of these substances have the feature of injectability, which means that the substance is injected into the desired place in the solution state and then turns into the gel, which makes it possible to administer them from a way with a minimal amount of invasion and eliminate the need for surgery to implant pre-formed materials. Gelation can be caused by a stimulus and/or spontaneously. Suppose this induces due to the effect of one or many stimuli. In that case, the material in question is called stimuli-responsive because it responds to the surrounding conditions. In this context, we introduce the different stimuli that cause gelation and investigate the different mechanisms of the transformation of the solution into the gel in them. Also, we study special structures, such as nano gels or nanocomposite gels.

Comparison of clinicodemographic characteristics and pattern of vascular involvement in 126 patients with Takayasu arteritis: a report from Iran and Turkey

Takayasu arteritis (TA) is an extremely uncommon vasculitis that primarily affects the aorta and its branches. Due to the genetic and ethnicity effect, a diverse array of TA clinical manifestations has been reported worldwide. The purpose of the present study was to compare the clinicodemographic characteristics and pattern of vascular involvement of Iranian and Turkish TA patients. This study was a retrospective, cross-sectional investigation of 126 TA patients in Iran and Turkey. All of the variables analyzed were extracted from historical medical records. In 126 TA patients, the ratio of females to males was 8.6:1, and the average age at onset of disease was 30.5±11.1 years. Fatigue (49.2%) and a weak or absent pulse (79.4%) were the most prevalent symptoms and signs, respectively. The most prevalent angiographic classifications were types V and I in Iranian patients (41.09%) and type I in the Turkish population (47.7%) The left subclavian artery was the vessel most frequently affected by TA (66.6%). Our findings indicated that there were no significant differences between the two countries in terms of clinicodemographic characteristics or vascular involvement. Some clinical manifestations, such as claudication, were more prevalent in the Turkish population due to a higher incidence of occlusive lesions in the right subclavian artery.

Context Matters: Social Psychological Factors That Underlie Academic Performance across Seven Institutions

To enhance equity and diversity in undergraduate biology, recent research in biology education focuses on best practices that reduce learning barriers for all students and improve academic performance. However, the majority of current research into student experiences in introductory biology takes place at large, predominantly White institutions. To foster contextual knowledge in biology education research, we harnessed data from a large research coordination network to examine the extent of academic performance gaps based on demographic status across institutional contexts and how two psychological factors, test anxiety and ethnicity stigma consciousness, may mediate performance in introductory biology. We used data from seven institutions across three institution types: 2-year community colleges, 4-year inclusive institutions (based on admissions selectivity; hereafter, inclusive), and 4-year selective institutions (hereafter, selective). In our sample, we did not observe binary gender gaps across institutional contexts, but found that performance gaps based on underrepresented minority status were evident at inclusive and selective 4-year institutions, but not at community colleges. Differences in social psychological factors and their impacts on academic performance varied substantially across institutional contexts. Our findings demonstrate that institutional context can play an important role in the mechanisms underlying performance gaps.

Nerve guidance conduit design based on self-rolling tubes

The current gold standard in peripheral nerve repair is nerve autografts for bridging gaps larger than a centimeter. However, autografts are associated with a low availability and the loss of function at the donor site. Nerve guidance conduits (NGCs) made of biocompatible and biodegradable materials reflect suitable alternatives. Clinically approved NGCs comprise either wraps that are rolled around the loose ends of the nerve or steady-state tubes; however, both lack internal guidance structures. Here, we established self-rolling NGCs to allow for gentle encapsulation of nerve cells together with supportive microenvironments, such as (1) an inner tube wall coating with a bioactive spider silk film, (2) an inner tube wall lining using an anisotropic spider silk non-woven mat, or (3) a luminal filler using an anisotropic collagen cryogel. Neuronal cells adhered and differentiated inside the modified tubes and formed neurites, which were oriented along the guidance structures provided by the spider silk non-woven mat or by the fibrillary structure of the collagen cryogel. Thus, our size-adaptable NGCs provide several features useful for peripheral nerve repair, and distinct combinations of the used elements might support and enhance the clinical outcome.

Thyroid metastasis of bladder transitional cell carcinoma

The thyroid gland is a rare site for cancer metastasis. We report a 75-year-old man who was referred with a history of hematuria and generalized bone pain for the past few months. He had a past history of partial left lobe thyroidectomy for follicular adenoma. Subsequently he was referred for a thyroid mass and a subtotal thyroidectomy showed a poorly-differentiated carcinoma. On the latest admission, the patient underwent resection of a bladder tumour with malignant histology and an immunohistochemical profile of CK7+/CK20+/34 Beta E12+/CEA-/PSA-. Re-examination of thyroid sections with immunohistochemical stains revealed the malignant cells to be CK7+/CK20+/34 Beta E12+/CEA-/TTF1-. The findings were compatible with metastasis of the bladder transitional cell carcinoma to the thyroid gland.Scans revealed multiple liver and bone metastases. The patient died 2 months after the diagnosis.

Cyclic mechanical loading promotes bacterial penetration along composite restoration marginal gaps

OBJECTIVES

Secondary caries is the most common reason for composite restoration replacement and usually forms between dentin and the filling. The objective of this study was to investigate the combined effect of cyclic loading and bacterial exposure on bacterial penetration into gaps at the interface between dentin and resin composite restorative material using a novel bioreactor system and test specimen design.

METHODS

Human molars were machined into 3mm thick disks with 2mm deep × 5 mm diameter cavity preparations into which composite restorations were placed. A ∼ 15-30 μm (small) or ∼ 300 μm wide (large) marginal gap was introduced along half of the interface between the dentin and restoration. Streptococcus mutans UA 159 biofilms were grown on each sample prior to testing each in a bioreactor both with and without cyclic loading. Both groups of samples were tested for 2 weeks and post-test biofilm viability was confirmed with a live-dead assay. Samples were fixed, mounted and cross-sectioned to reveal the gaps and observe the depth of bacterial penetration.

RESULTS

It was shown that for large gap samples the bacteria easily penetrated to the full depth of the gap independent of loading or non-loading conditions. The results for all cyclically loaded small gap samples show a consistently deep bacterial penetration down 100% of the gap while the average penetration depth was only 67% for the non-loaded samples with only two of six samples reaching 100%.

SIGNIFICANCE

A new bioreactor was developed that allows combining cyclic mechanical loading and bacterial exposure of restored teeth for bacterial biofilm and demineralization studies. Cyclic loading was shown to aid bacterial penetration into narrow marginal gaps, which could ultimately promote secondary caries formation.

Characterization of structural, mechanical and nano-mechanical properties of electrospun PGS/PCL fibers

Structural and mechanical properties of aligned PGS/PCL nanofibers for cornea tissue engineering are studied and compared to natural corneal stroma.

Human liver regeneration is characterized by the coordinated expression of distinct microRNA governing cell cycle fate

In the absence of adequate compensatory regeneration, overwhelming liver damage can cause acute liver failure (ALF) and death without emergent liver transplantation (LT). Auxiliary LT produces satisfactory outcomes in this setting, with the prospect of native liver regeneration sustaining long-term survival. Since animal models only partially recapitulate human liver regeneration, we investigated the molecular mechanisms controlling it in this unique LT setting, as an exemplar of human liver regeneration. We demonstrate coordinated changes in expression of microRNA (miRNA) during regeneration that drive proliferation, innate immunity and angiogenesis. In contrast, failed regeneration in a similar cohort is associated with distinct miRNA enforcing cell cycle inhibition and DNA methylation. The miRNA expression associated with successful or failed regeneration when recapitulated in vitro, triggered expression of cardinal regeneration-linked genes promoting cell cycle entry or inhibition, respectively. Furthermore, inhibition of miRNA 150, 663 and 503, whose downregulation is associated with successful regeneration, induced cell proliferation which a key determinant of successful regeneration. Our data indicate that human liver regeneration may be orchestrated by distinct miRNA controlling key regeneration-linked processes including hepatocyte proliferation. To our knowledge this is the first characterization of molecular processes associated with human liver regeneration.

Artificial skin ridges enhance local tactile shape discrimination

One of the fundamental requirements for an artificial hand to successfully grasp and manipulate an object is to be able to distinguish different objects' shapes and, more specifically, the objects' surface curvatures. In this study, we investigate the possibility of enhancing the curvature detection of embedded tactile sensors by proposing a ridged fingertip structure, simulating human fingerprints. In addition, a curvature detection approach based on machine learning methods is proposed to provide the embedded sensors with the ability to discriminate the surface curvature of different objects. For this purpose, a set of experiments were carried out to collect tactile signals from a 2 × 2 tactile sensor array, then the signals were processed and used for learning algorithms. To achieve the best possible performance for our machine learning approach, three different learning algorithms of Naïve Bayes (NB), Artificial Neural Networks (ANN), and Support Vector Machines (SVM) were implemented and compared for various parameters. Finally, the most accurate method was selected to evaluate the proposed skin structure in recognition of three different curvatures. The results showed an accuracy rate of 97.5% in surface curvature discrimination.

Hydrodynamic gene delivery to the pig liver via an isolated segment of the inferior vena cava

Hydrodynamic gene delivery is an attractive option for non-viral liver gene therapy, but requires evaluation of efficacy, safety and clinically applicable techniques in large animal models. We have evaluated retrograde delivery of DNA to the whole liver via the isolated segment of inferior vena cava (IVC) draining the hepatic veins. Pigs (18-20 kg weight) were given the pGL3 plasmid via two programmable syringe pumps in parallel. Volumes corresponding to 2% of body weight (360-400 ml) were delivered at 100 ml s(-1) via a Y connector. The IVC segment pressure, portal venous pressure, arterial pressure, electrocardiogram (ECG) and pulse were monitored. Concurrent studies were performed in rats for interspecies comparisons. The hydrodynamic procedure generated intrahepatic vascular pressures of 101-126 mm Hg, which is approximately 4 times higher than in rodents, but levels of gene delivery were approximately 200-fold lower. Suprahepatic IVC clamping caused a fall in arterial pressure, with the development of ECG signs of myocardial ischaemia, but these abnormalities resolved rapidly. The IVC segment approach is a clinically acceptable approach to liver gene therapy. However, it is less effective in pigs than in rodents, possibly because of larger liver size or a less compliant connective tissue framework.

Evaluation of intravenous hydrocortisone in reducing headache after spinal anesthesia: a double blind controlled clinical study [corrected]

BACKGROUND

Headache after spinal anesthesia is a common complication is patients undergoing this procedure. In this study we evaluated the efficacy of intravenous hydrocortisone in the treatment of headache after spinal anesthesia in women who have undergone cesarean section.

METHODS

Sixty patients with headache after spinal anesthesia were included. Patients randomly allocated into two groups, 30 patients received only conventional therapy (complete bed rest, hydration, acetaminophen and pethidine). Other 30 patients received conventional therapy plus intravenous hydrocortisone (200 mg first, then 100 mg TID for 48 hours). Mean (+/- SD) of headache intensity at 0, 6, 24, and 48 hours after beginning of treatment was measured using visual analog scale.

RESULTS

There was no significant difference in headache intensity between two groups before beginning of treatment. After 6 hours, the mean of headache intensity in 30 patients treated conventionally was 6.63 (+/- 1.35) while it was 2.77 (+/- 1.07) in other patients received intravenous hydrocortisone too (p <0.001). After 24 hours, mean headache intensity was 3.87 (+/- 1.63) in conventionally treated group versus 0.73 (+/- 0.74) in hydrocortisone group (p <0.001). After 48 hours, mean headache intensity was 1.87 (+/- 0.93) in conventionally treated group versus 0.63 (+/- 0.61) in hydrocortisone group (p = 0.001).

CONCLUSIONS

This study showed the therapeutic effects of intravenous hydrocortisone in reducing headache after spinal anesthesia in women who underwent cesarean section. Its mechanism of action is yet to be determined.

Effect of a new phenanthroline derivative on testicular tissue and serum testosterone concentration and its contraceptive affects on adult Balb/C mouse strain

In this research, the effect of 2, 6-diaminopyridinum as a new phenanthroline derivative was studied on the hypophysis-gonad axis, testicular tissue and sperm production in male Balb/C mice. Fifty adult male Balb/C mice were divided in five groups. First group was considered as untreated control. Saline was injected to second group and the remaining three groups received intraperitoneal injection of 15, 20 and 25 mg kg(-1) of 2, 6-diaminopyridinum every other day for 20 days. The LD50 was determined to be 35 mg kg(-1) body weight. The testicular tissues were studied morphologically and the serum concentration of FSH, LH and testosterone were measured. The results showed that 25 mg kg(-1) diaminopyridinum decreased the number of germ cells significantly and serum testosterone level with no change on FSH and LH levels. This study indicates that 25 mg kg(-1) of phenanthroline may directly affect testicular tissue causing a lower testosterone level and spermatogenesis in mice.

The block of central vasopressin V1 but not V2 receptors suppresses grooming behavior and hypothermia induced by intracerebroventricular vasopressin in male rats

The role of central vasopressin V1 receptors in grooming behavior induced by vasopressin and oxytocin was studied in male rats of the Wistar strain. The intracerebroventricular (ICV) injection of vasopressin (3 micrograms/5 microliters) induced hypothermia and enhanced novelty-induced grooming behavior. Enhanced grooming but not hypothermia was also induced by ICV injection of oxytocin (3 micrograms/5 microliters). The central administration of a selective vasopressin V1 receptor antagonist prevented the stimulating action of vasopressin on novelty-induced grooming and its hypothermic effect. The ICV injection of a selective vasopressin V2 receptor antagonist failed to affect vasopressin-induced grooming and hypothermic effect. An increase in core temperature was observed in oxytocin-injected animals pretreated with the vasopressin V1 receptor antagonist. Furthermore, pretreatment with the antagonist did not affect grooming induced by oxytocin. These results suggest that enhancement of grooming behavior and influence on thermoregulation are differently regulated by central receptors for vasopressin and oxytocin.