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Peptides are the most abundant biological compounds in the cells that act as enzymes, hormones, structural element, and antibodies. Mostly, peptides have problems to move across the cells because of their size and poor cellular penetration. Therefore, a carrier that could transfer peptides into cells is ideal and would be effective for disease treatment. Until now, plenty of polymers, e.g., polysaccharides, polypeptides, and lipids were used in drug delivery. Hydrogels made from polysaccharides showed significant development in targeted delivery of peptide hormones because of their natural characteristics such as networks, pore sizes, sustainability, and response to external stimuli. The main aim of the present review was therefore, to gather the important usages of the hydrogels as a carrier in peptide hormone delivery and their application in tissue engineering and regenerative medicine.

Infections caused by extended-spectrum β-lactamases (ESBLs) producing bacteria, including Klebsiella pneumoniae have increasingly subjected to therapeutic limitations and patients with these infections are at high risk for treatment failure, long hospital stays, high health care costs, and high mortality. The aim of this study was to screen the prevalence of the blaTEM,blaCTX-M and blaSHV ESBL genes in K. pneumoniae strains isolated from nosocomial urinary tract infections (UTIs). During the March 2016 to December 2017, one hundred isolates of K. pneumoniae were collected from urine specimens of patients suffering from nosocomial UTI referred to Khatam Al-Anbia hospital in Shahrud, north-central Iran. All isolates were identified by standard bacteriological tests. The pattern of antibiotic susceptibility was determined according to the CLSI guidelines. The presence of the ESBLs was investigated using the double-disc synergy test (DDST). Polymerase chain reaction technique was used to detect the blaTEM, blaCTX-M and blaSHV genes in DDST positive isolates. Most isolates showed remarkable resistance to tested antibiotics with highest rate against nitrofurantoin (75%) and trimethoprim/sulfamethoxazole (65%). The imipenem was the most effective antibiotic against K. pneumoniae isolates. ESBL phenotype was detected in 50 (50%) of isolates. The prevalence of blaTEM, blaCTX-M and blaSHV genes among 50 ESBLs-positive isolates was 25 (50%), 15 (30%) and 35 (70%) respectively. The blaTEM and blaSHV genes were seen in 25 isolates (50%) simultaneously. The findings of this study indicated the 50% frequency rate of ESBL-producing K. pneumoniae in our geographic region. Since the treatment of infections caused by this bacterium is associated with many limitations, this high prevalence is a warning sign to adopt new control policies to prevent further spread of this microorganism.

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The present study was designed for microwave assisted synthesis of zinc nanoparticles (Zn NPs) using Lavandula vera leaf extract in the presence of ZnSO (1mM). The biogenic Zn NPs were then characterized using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), UV-visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) techniques. Thereafter, the cytotoxic effect of ZnSO and Zn NPs on different cell lines was investigated by MTT-based cytotoxicity assay and their antioxidant properties were assessed using DPPH scavenging activity and reducing power assay. The SEM micrograph showed that the Zn NPs had spherical shape with the size range of 30-80nm. For A549, MCF-7, HT-29, and Caco-2 cell lines treated with Zn NPs, the concentration necessary causing 50% cell death (IC) was found to be 22.3±1.1μgmL, 86±3.7μgmL, 10.9±0.5μgmL, and 56.2±2.8μgmL, respectively. In the case of ZnSO, the same results (IC) were observed at concentration of 81.6±1.3μgmL (A549), 121.0±2.4μgmL (MCF-7), 43.0±1.4μgmL (HT-29), and 85.7±2.3μgmL (Caco-2). The obtained results of antioxidant activity showed that the IC values of butylated hydroxyanisole (BHA) and Zn NPs were 44μgmLand 65.3μgmL, respectively, while ZnSO at concentration of 200μgmL exhibited only 10.9% DPPH radical scavenging effect. Moreover, the reducing power of Zn NPs and BHA were significantly higher than ZnSO (p<0.05). To sum up, application of L. vera leaf extract combined with microwave heating energy led to simple and fast formation of Zn nanostructures exhibited higher antioxidant and cytotoxic activity compared to soluble Zn ions. However, identification of the related mechanisms merit further studies.

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Background: Recent theranostic (therapeutic or diagnostic) applications of tellurium nanoparticles have attracted a great interest for development of diff erent methods for synthesis of this valuable nanostructure, especially via biological resources. Objectives: In the present study, the antimicrobial and antioxidant eff ects of the tellurium nanorods (Te NRs) biosynthesized by a bacterial strain Pseudomonas pseudoalcaligenes strain Te were evaluated. Materials and Methods:The antimicrobial eff ect of Te NRs and potassium tellurite against diff erent bacterial and fungal pathogens was assessed by microdilution method. Furthermore, the disk diff usion method was used to evaluate the antibacterial eff ect of the biogenic Te NRs and potassium tellurite against methicillin-resistant Staphylococcus aureus, alone or in combination with various antibiotics. Also, the biogenic Te NRs were investigated for antioxidant activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and reducing power assay. Results: Transmission electron micrograph (TEM) of the purifi ed Te NRs showed individual and rod-shaped nanostructure (~22 nm diameter by 185 nm in length). Based on the data obtained from both microdilution and disk diff usion method the K 2 TeO 3 exhibited a higher antibacterial and antifungal activity compared to the Te NRs. The measured IC 50 for the biogenic Te NRs (i.e. DPPH radical scavenging activity) was found to be 24.9 μg.mL -1 , while, K 2 TeO 3 has represented only 17.6 ± 0.8 % DPPH radical scavenging eff ect at the concentration of 160 μg.mL -1 . The reducing power assay revealed a higher electron-donating activity for Te NRs compared to K 2 TeO 3 . Conclusions: Based on the data obtained from both microdilution and disk diff usion method the K 2 TeO 3 exhibited a higher antimicrobial and antifungal activity than Te NRs. Te NRs didn't show the antibacterial eff ect against the tested bacterial strain: MRSA and showed an inhibitory eff ect and antibacterial activity of the eff ective antibiotics. However, more studies should be performed to explore the action mechanism of the produced biogenic Te NRs.