Avicenna Journal of Medical Biotechnology
Volume:12 Issue: 4, 2020 Oct Dec

Cellular transplantation, due to the low regenerative capacity of the Central Nervous System (CNS), is one of the promising strategies in the treatment of neurodegenerative diseases. The design and application of scaffolds mimicking the CNS extracellular matrix features (biochemical, bioelectrical, and biomechanical), which affect the cellular fate, are important to achieve proper efficiency in cell survival, proliferation, and differentiation as well as integration with the surrounding tissue. Different studies on natural materials demonstrated that hydrogels made from natural materials mimic the extracellular matrix and supply microenvironment for cell adhesion and proliferation. The design and development of cellular microstructures suitable for neural tissue engineering purposes require a comprehensive knowledge of neuroscience, cell biology, nanotechnology, polymers, mechanobiology, and biochemistry. In this review, an attempt was made to investigate this multidisciplinary field and its multifactorial effects on the CNS microenvironment. Many strategies have been used to simulate extrinsic cues, which can improve cellular behavior toward neural lineage. In this study, parallel and align, soft and injectable, conductive, and bioprinting scaffolds were reviewed which have indicated some successes in the field. Among different systems, three-Dimensional (3D) bioprinting is a powerful, highly modifiable, and highly precise strategy, which has a high architectural similarity to tissue structure and is able to construct controllable tissue models. 3D bioprinting scaffolds induce cell attachment, proliferation, and differentiation and promote the diffusion of nutrients. This method provides exceptional versatility in cell positioning that is very suitable for the complex Extracellular Matrix (ECM) of the nervous system.

Inhibition of biofilm formation is essential for the prevention and treatment of urinary tract infection. This study was aimed to identify the probiotic potential of Lactobacillus strains isolated from kefir and evaluate their antimicrobial and antibiofilm activities against Uropathogenic Escherichia coli</em> (UPEC). 

Twelve Lactobacillus strains were evaluated. Antimicrobial and antibiofilm activities of Cell Free Supernatant (CFS) of the Lactobacillus strains against UPEC isolates were evaluated by agar well diffusion method and crystal violet assay, respectively. Probiotic potential of selected isolates was assessed by analyzing their tolerance to acidic pH and bile salts, auto-aggregation ability, co-aggregation with Escherichia coli (E. coli)</em> and hemolytic activity. The isolates were identified by phenotypic and 16S rRNA gene sequencing.

  The CFS of all lactobacilli strains was able to inhibit UPEC isolates even after neutralization. Four out of 12 isolates inhibited the biofilm formation by UPEC in the range 62-75%. The viability under acidic condition varied among the isolates ranging from 6-89.8%. All the isolates could tolerate the 0.3% bile and eight isolates showed the adaptation time of less than 1 hr</em>. All the strains exhibited co-aggregation with E. coli</em>. Auto-aggregation was highly correlated with co-aggregation of all lactobacilli strains with E. coli</em> (r=0.889, p<0.001). The isolates with satisfactory probiotic potential and higher ability of biofilm inhibition and antibacterial activity belonged to the species Lactobacillus</em> rhamnosus</em> and Lactobacillus paracasei</em>.

All four selected probiotic strains exhibited antimicrobial and antibiofilm activities, which suggest potential applications for controlling or preventing infections caused by UPEC.

Remaining pharmaceutical compounds cause environmental pollution. Therefore, refining these compounds has become a major challenge. In this study, the function of eliminating Cefixime (CFX) using rice starch was evaluated under controlled conditions.

Response Surface Methodology (RSM) was used to design, analyze, and optimize experiments, and the interaction between four variables including pH (3-9), rice starch dose (0–300 mg/L</em>), CFX initial concentration (0–16 mg/L</em>) and time (20–120 min</em>) was investigated on CFX removal.

The optimum pH, starch dose, initial concentration and time were 4.5, 225 mg/L</em>, 7.9 mg/L</em> and 95 min</em>, respectively. The maximum efficiency of CFX removal was 70.22%. According to RSM, this study follows a quadratic model (R2</sup>=0.954).

Rice starch has been successful in removing CFX from the aqueous solution. Therefore, it is recommended to utilize this process to remove CFX from aqueous solutions.

Tooth agenesis is one of the most common developmental anomalies in human and the main reasons for its occurrence are still unknown. Mutations of several genes such as PAX9</em>, MSX1</em>, AXIN2</em>, KDF1</em> and WNT10A</em> have been reported which are associated with non-syndromic tooth agenesis. However, PAX9</em>, MSX1</em> and WNT10A</em> are commonly reported in the literature. Hence, the aim of this study was to investigate the mutations of these genes in 4 Iranian families with non-syndromic tooth agenesis.

DNA extractions from peripheral blood cells of patients with non-syndromic tooth agenesis from 4 unrelated Iranian families were performed by salting out method, and the candidate genes were amplified then followed by Sanger sequencing method.

One missense variant (rs4904210) and 4 Single Nucleotide Polymorphisms (SNPs) (rs2236007, rs12883298, rs12882923 and rs12883049) were found in PAX9</em> gene. Five variants (rs149370601, rs8670, rs186861426 and rs774949973) including a missense variant (rs36059701) were detected in MSX1</em> gene and no variants were found in WNT10A</em> gene.

All variants were analyzed based on bioinformatics websites and Iranian gene databases, and as a result, it was revealed that variants of PAX9</em>, MSX1</em> and WNT10A</em> may not play a role in non-syndromic tooth agenesis among Iranian cases.

The main problem in treatment of leukemia patients is the chemotherapy resistance which is a main concern in recent years. The cause of chemotherapy drug resistance is related to MDR</em> gene which is located on chromosome 7 (7q21-31) and it is mainly connected with energy-dependent efflux (P-glycoprotein). This study was conducted to assess the correlation between MDR polymorphism and chemotherapy efficiency with Vincristine in a sample of Iraqi Acute Myeloid Leukemia (AML) patients.

The blood sample of 200 AML patients and 200 controls were collected and the frequency of rs2032582 was calculated through sequencing and then the role of different genetic patterns was evaluated on cancer cells by MTT assay.

The results indicate that GG and TT genotypes (20 and 20.5% from total patients count) are more frequent in Iraqi AML patients than other genetic patterns in MDR</em> gene and also the genotype TA is more sensitive to Vincristine chemotherapy than other genotypes.

It seems that genetic pattern is the main factor in determination of chemotherapy of AML patients, and patients should not undergo chemotherapy with such drugs, especially Vincristine.

Severe Acute Respiratory Syndrome-coronavirus 2 (SARS-CoV-2) is a new virus with a global pandemic. Yet, no vaccine or efficient treatments are found against the disease. The viral RNA dependent RNA Polymerase (RdRP) is a suitable target for developing antiviral agents. SARS-CoV-2 RdRP was employed to test its binding activity with some drugs.

Using some docking methods, RdRP was targeted by Milbemycins (MMs), Ivermectin (IMT), Baloxavir Marboxil (BM), and Tadalafil (TF), a phosphodiesterase type 5 inhibitor.

MM-A3 5-oxime (MMA35O), MM-A3 (MMA3), MM-A4 5-oxime (MMA45O), IMT, BM, and TF showed the highest binding affinity to RdRp.

The drugs used in the present computational investigation are effective against the SARS-CoV-2 RdRP with high affinity values especially, milbemycins, ivermectin, and Baloxavir marboxil, which could further be studied in laboratory and clinical trials for saving millions of lives around the world.

Electrospray (Electrohydrodynamic atomization) has been introduced as a novel approach to prepare nanoparticles. This work aimed to prepare SLNs through electrospray and evaluate factors affecting particle size of prepared Solid Lipid Nanoparticles (SLNs).

SLNs were prepared by electrospray method. To study the factors affecting particle size of SLNs, Artificial Neural Networks (ANNs) were employed. Four input variables, namely, Tween 80 concentration, lipid concentration, flow rate, and polymer to lipid ratio were analyzed through ANNs and particle size was the output.

The analyzed model presented concentration of Tween 80 (surfactant) and lipid as effective parameters on particle size. By increasing surfactant and decreasing lipid concentration, minimum size could be obtained, while flow rate and polymer to lipid ratio appeared not to be effective.

Concentration of surfactant/lipid plays the most important role in determining the size.