Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Curr Pharm Des ; 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38482625

RESUMO

BACKGROUND: Interleukin 2 (IL-2) is a vital cytokine in the induction of T and NK cell responses, the proliferation of CD8+ T cells, and the effective treatment of human cancers, such as melanoma and renal cell carcinoma. However, widespread use of this cytokine is limited due to its short half-life, severe toxicity, lack of specific tumor targeting, and activation of Treg cells mediated by high-affinity interleukin-2 receptors. OBJECTIVE: In this study, a tumor-targeting LIV-1 VHH-mutIL2 immunocytokine with reduced CD25 (α chain of the high-affinity IL-2 receptor) binding activity was developed to improve IL-2 half-life by decreasing its renal infiltration in comparison with wild and mutant IL-2 molecules. METHODS: The recombinant immunocytokine was designed and expressed. the biological activity of the purified fusion protein was investigated in in vitro and in vivo experiments. RESULTS: The fusion protein represented specific binding to MCF7 (the breast cancer cell line) and more efficient cytotoxicity than wild-type IL-2 and mutant IL-2. the PK parameters of the recombinant immunocytokine were also improved in comparison to the IL-2 molecules. CONCLUSION: The observed results showed that LIV1-mIL2 immunocytokine could be considered an effective agent in the LIV-1-targeted treatment of cancers due to its longer half-life and stronger cytotoxicity.

2.
J Pharm Sci ; 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38417791

RESUMO

Amphiphilic peptides hold great potential as drug delivery systems. A popular peptide design approach has been to place amino acids in the peptide sequence based on their known properties. On the other hand, the directed discovery approach aims to screen a sequence space for a desired property. However, screening amphiphilic peptides for desirable drug delivery properties is not possible without a quantity that is predictive of these properties. We studied the predictive power of critical aggregation concentration (CAC) values on the drug delivery performance of a series of amphiphilic peptides with different hydrophobic tails and close CAC values. The CAC values were predicted by our previously developed model and doxorubicin was used as a model hydrophobic drug. All peptides showed close drug loading, entrapment efficiency, and release profile. They also formed similar spherical particles by assembling in reverse ß-sheet arrangements regardless of drug presence. Moreover, the assembled particles were able to accumulate doxorubicin inside ordinary as well as drug-resistant breast cancer cells and enhance its toxicity up to 39 and 17 folds, respectively. It can be concluded that similar drug delivery properties displayed by the peptides can be attributed to their similar hydrophilic-lipophilic balance as reflected in their close CAC values.

3.
Sci Rep ; 13(1): 21851, 2023 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-38071203

RESUMO

The procedures currently used for hepatitis B (HB) detection are not suitable for screening, clinical diagnosis, and point-of-care testing (POCT). Therefore, we developed and tested a QCM-based immunosensor by surface modification with AuNP-PEIs to amplify the signal and provide an oriented-immobilization surface. The AuNP-PEIs were characterized by ICP-Mass, UV/Vis, DLS, FE-SEM, and ATR-FTIR. After coating AuNP-PEIs on the gold electrode surface, anti-HBsAg antibodies were immobilized using NHS/EDC chemistry based on response surface methodology (RSM) optimization. The efficiency of the immunosensor was assessed by human sera and data were compared to gold-standard ELISA using receiver-operating-characteristic (ROC) analysis. FE-SEM, AFM, EDS, and EDS mapping confirmed AuNP-PEIs are homogeneously distributed on the surface with a high density and purity. After antibody immobilization, the immunosensor exhibited good recognition of HBsAg with a calibration curve of ∆F = - 6.910e-7x + 10(R2 = 0.9905), a LOD of 1.49 ng/mL, and a LOQ of 4.52 ng/mL. The immunosensor yielded reliable and accurate results with a specificity of 100% (95% CI 47.8-100.0) and sensitivity of 100% (95% CI 96.2-100.0). In conclusion, the fabricated immunosensor has the potential as an analytic tool with high sensitivity and specificity. However, further investigations are needed to convert it to a tiny lab-on-chip for HB diagnosis in clinical samples.


Assuntos
Técnicas Biossensoriais , Hepatite B , Nanopartículas Metálicas , Humanos , Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , Polietilenoimina , Ouro , Técnicas de Microbalança de Cristal de Quartzo/métodos , Imunoensaio/métodos , Hepatite B/diagnóstico , Limite de Detecção
4.
J Biomol Struct Dyn ; : 1-17, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37553776

RESUMO

Antiviral drugs are currently used to prevent or treat viral infections like influenza A Virus (IAV). Nonetheless, annual genetic mutations of influenza viruses make them resistant to efficient treatment by current medications. Antiviral peptides have recently attracted researchers' attention and can potentially supplant the current medications. This study aimed to design peptides against IAV propagation. For this purpose, P2 and P3 peptides were computationally designed based on the HCDR3 region of the C05 antibody (a monoclonal antibody that neutralizes influenza HA protein and inhibits the virus attachment). The synthesized peptides were tested against the influenza A virus (A/Puerto Rico/8/34 (H1N1)) in vitro, and the most efficient peptide was selected for in vivo experiments. It was shown that the designed peptide shows much more prophylactic and therapeutic effects against the virus. These findings demonstrated that the designed peptide can control the virus infection without any cytotoxicity effect. Antiviral peptide design is acknowledged as a critical tactic to manage viral infections by preventing viral binding to the host cells.Communicated by Ramaswamy H. Sarma.

5.
RSC Adv ; 13(32): 21873-21881, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37475756

RESUMO

A novel and biologically active nanobiocomposite is synthesized based on carbon nitride nanosheet (g-C3N4) based carboxymethylcellulose hydrogels with embedded zinc ferrite nanoparticles. Physical-chemical aspects, morphological properties, and their multifunctional biological properties have been considered in the process of evaluation of the synthesized structure. The hydrogels' compressive strength and compressive modulus are 1.98 ± 0.03 MPa and 3.46 ± 0.05 MPa, respectively. Regarding the biological response, it is shown that the nanobiocomposite is non-toxic and biocompatible, and hemocompatible (with Hu02 cells). In addition, the developed material offers a suitable antibacterial activity for both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

6.
World J Microbiol Biotechnol ; 39(9): 227, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37326689

RESUMO

The membrane enzyme of hyaluronan synthase (HAS) is the key enzyme in hyaluronic acid (HA) biosynthesis by coupling UDP-sugars. Prior studies proposed the C-terminus region of HAS enzyme mediates the production rate and molecular weight of HA. The current study describes the isolation and characterizations of a transmembrane HAS enzyme isolated from Streptococcus equisimilis Group G (GGS-HAS) in vitro. The effect of transmembrane domains (TMDs) on HA productivity was determined and the shortest active variant was also identified by recombinant expression of full-length and five truncated forms of GGS-HAS in Escherichia coli. We found that the GGS-HAS enzyme is longer than that of S. equisimilis group C (GCS-HAS) which includes three more residues (LER) at the C-terminus region (positions 418-420) and also one-point mutation at position 120 (E120D). Amino acid sequence alignment demonstrated 98% and 71% identity of GGS-HAS with that of S. equisimilis Group C and S. pyogenes Group A, respectively. The in vitro productivity of the full-length enzyme was 35.57 µg/nmol, however, extended TMD deletions led to a reduction in the HA productivity. The HAS-123 variant showed the highest activity among the truncated forms, indicating the essential role of first, second, and third TMDs for the full activity. Despite a decline in activity, the intracellular variant can still mediate the binding and polymerization of HA without any need for TMDs. This significant finding suggests that the intracellular domain is the core for HA biosynthesis in the enzyme and other domains are probably involved in other attributes including the enzyme kinetics that affect the size distribution of the polymer. However, more investigations on the recombinant forms are still needed to confirm clearly the role of each transmembrane domain on these properties.


Assuntos
Glucuronosiltransferase , Ácido Hialurônico , Hialuronan Sintases/genética , Hialuronan Sintases/química , Ácido Hialurônico/química , Ácido Hialurônico/metabolismo , Glucuronosiltransferase/genética , Glucuronosiltransferase/química , Glucuronosiltransferase/metabolismo , Polimerização
7.
AMB Express ; 13(1): 63, 2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37354246

RESUMO

Hyaluronic acid (HA), composed of glucuronic acid (GlcUA) and N-acetyl glucoseamine (GlcNAc), is a versatile biopolymer with high commercial value and innumerous physiological roles and pharmaceutical applications. The hasA gene has main role in HA biosynthesis by Streptococcus strain as a natural producer. The hasB and hasC genes are also mediate GlcUA precursor biosynthesis. In the present study, S. equisimilis hasA gene; B. subtilis tuaD and gtaB genes for GlcUA precursors enhancement, and vgb gene coding bacterial hemoglobin as an oxygen provider were used to construct the B. subtilis strain for HA production. RBSHA (hasA), RBSHA2 (hasA/tuaD/gtaB), and RBSHA3 (hasA/tuaD/gtaB/vgb) strains were developed and confirmed through genotype and phenotype analysis. After HA production and purification, FTIR spectroscopy confirmed the produced HA structures. HA assay showed the highest HA titer for RBSHA3 (2.1 ± 0.18 mg/ml) and then RBSHA2 (1.9 ± 0.03 mg/ml), and RBSHA (0.6 ± 0.14 mg/ml). Statistical analysis indicated there is no significant difference in HA titer between RBSHA2 and RBSHA3 strains (p-value > 0.05), however, these strains produced HA approximately 4-fold higher than that of RBSHA strain. Agarose gel electrophoresis showed the same molecular weight (< 30 kDa) of produced HA by strains. Dynamic light scattering (DLS) revealed all HA polymers had a relatively low polydispersity index (PDI < 0.5). These findings demonstrate the successful GlcUA biosynthetic pathway engineering strategy in improving HA yield by recombinant B. subtilis, metabolically-robust, and industrially potential strain.

8.
J Biotechnol ; 367: 71-80, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37028560

RESUMO

In this work, a magnetic nanobiocomposite scaffold based on carboxymethylcellulose (CMC) hydrogel, silk fibroin (SF), and magnetite nanoparticles was fabricated. The structural properties of this new magnetic nanobiocomposite were characterized by various analyses such as FT-IR, XRD, EDX, FE-SEM, TGA and VSM. According to the particle size histogram, most of the particles were between 55 and 77 nm and the value of saturation magnetization of this nanobiocomposite was reported 41.65 emu.g- 1. Hemolysis and MTT tests showed that the designed magnetic nanobiocomposite was compatible with the blood. In addition, the viability percentage of HEK293T normal cells did not change significantly, and the proliferation rate of BT549 cancer cells decreased in its vicinity. EC50 values for HEK293T normal cells after 48 h and 72 h were 3958 and 2566, respectively. Also, these values for BT549 cancer cells after 48 h and 72 h were 0.4545 and 0.9967, respectively. The efficiency of fabricated magnetic nanobiocomposite was appraised in a magnetic fluid hyperthermia manner. The specific absorption rate (SAR) of 69 W/g (for the 1 mg/mL sample at 200 kHz) was measured under the alternating magnetic field (AMF).


Assuntos
Fibroínas , Hipertermia Induzida , Neoplasias , Humanos , Fibroínas/farmacologia , Fibroínas/química , Hidrogéis , Carboximetilcelulose Sódica/farmacologia , Carboximetilcelulose Sódica/química , Espectroscopia de Infravermelho com Transformada de Fourier , Células HEK293 , Fenômenos Magnéticos , Neoplasias/tratamento farmacológico
9.
J Transl Med ; 21(1): 13, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36627666

RESUMO

BACKGROUND: The pathogenicity of pneumococcus with high morbidity, mortality, and multi-drug resistance patterns has been increasing. The limited coverage of the licensed polysaccharide-based vaccines and the replacement of the non-vaccine serotypes are the main reasons for producing a successful serotype-independent vaccine. Pneumococcal surface protein A (PspA) is an extremely important virulence factor and an interesting candidate for conserved protein-based pneumococcal vaccine classified into two prominent families containing five clades. PspA family-elicited immunity is clade-dependent, and the level of the PspA cross-reactivity is restricted to the same family. METHODS: To cover and overcome the clade-dependent immunity of the PspAs in this study, we designed and tested a PspA1-5c+p vaccine candidate composed of the highest immunodominant coverage of B- and T-cell epitope truncated domain of each clade focusing on two cross-reactive B and C regions of the PspAs. The antigenicity, toxicity, physicochemical properties, 3D structure prediction, stability and flexibility of the designed protein using molecular dynamic (MD) simulation, molecular docking of the construct withHLADRB1*(01:01) and human lactoferrin N-lop, and immune simulation were assessed using immunoinformatics tools. In the experimental section, after intraperitoneal immunization of the mice with Alum adjuvanted recombinant PspA1-5c+p, we evaluated the immune response, cross-reactivity, and functionality of the Anti-PspA1-5c+p antibody using ELISA, Opsonophagocytic killing activity, and serum bactericidal assay. RESULTS: For the first time, this work suggested a novel PspA-based vaccine candidate using immunoinformatics tools. The designed PspA1-5c+p protein is predicted to be highly antigenic, non-toxic, soluble, stable with low flexibility in MD simulation, and able to stimulate both humoral and cellular immune responses. The designed protein also could interact strongly with HLADRB1*(01:01) and human lactoferrin N-lop in the docking study. Our immunoinformatics predictions were validated using experimental data. Results showed that the anti-PspA1-5c+p IgG not only had a high titer with strong and same cross-reactivity coverage against all pneumococcal serotypes used but also had high and effective bioactivity for pneumococcal clearance using complement system and phagocytic cells. CONCLUSION: Our findings elucidated the potential application of the PspA1-5c+p vaccine candidate as a serotype-independent pneumococcal vaccine with a strong cross-reactivity feature. Further in-vitro and in-vivo investigations against other PspA clades should be performed to confirm the full protection of the PspA1-5c+p vaccine candidate.


Assuntos
Infecções Pneumocócicas , Humanos , Animais , Camundongos , Sorogrupo , Infecções Pneumocócicas/prevenção & controle , Epitopos , Lactoferrina , Simulação de Acoplamento Molecular , Proteínas de Bactérias , Streptococcus pneumoniae , Vacinas Pneumocócicas , Anticorpos , Anticorpos Antibacterianos , Camundongos Endogâmicos BALB C
10.
Mol Biotechnol ; 65(5): 766-773, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36203034

RESUMO

Angiogenesis, the formation of new vessels, is a critical step in the malignancy progression of solid tumors. Many investigations have demonstrated the usefulness of immunotoxins to halt angiogenesis in solid tumors. Pharmaceutically, Vascular Endothelial Growth Factor (VEGF) can deliver coupled toxins to the tumor vessels through VEGF Receptors. In the current study, we designed, expressed, and assessed the in vitro and in vivo toxicities of a novel immunotoxin consisting of mouse VEGF and heminecrolysin toxin (mVEGF-HNc). The fusion protein was expressed in E. coli and purified via Ni+2 affinity chromatography. The biological activity of immunotoxin was evaluated on NIH/3T3 cells and TC1-tumorized mouse model. The mVEGF-NHc showed significant cytotoxicity on the cells as VEGFR-expressing cells. Moreover, the size of the tumor in the mVEGF-HNc-treated group started to reduce after six injections, while it continued to grow in the PBS-received mice. Efficacious targeting of solid tumor cells via mVEGF-HNc suggests its prospective therapeutic potential for cancer therapy.


Assuntos
Imunotoxinas , Neoplasias , Camundongos , Animais , Fator A de Crescimento do Endotélio Vascular , Escherichia coli/metabolismo , Fatores de Crescimento do Endotélio Vascular , Neoplasias/tratamento farmacológico
11.
Int J Biol Macromol ; 224: 1478-1486, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36328271

RESUMO

In the current study, sodium alginate (SA) and tannic acid (TA), in the presence of calcium chloride as a cross-linker, were used to fabricate a nanocomposite scaffold. With the addition of silk fibroin (SF), the strength of the synthesized composite was increased. Fe3O4 magnetic nanoparticles (MNPs) led to the usage of this magnetic nanocomposite in hyperthermia applications. Various properties of this scaffold were investigated by field emission scanning electron microscope (FE-SEM), thermogravimetric analysis (TGA), Fourier-transformed infrared (FT-IR), energy dispersive X-Ray (EDX), Vibrating- sample magnetometer (VSM). A hemolytic assay of this magnetic nanocomposite demonstrated that about 100 % of red blood cells (RBCs) survived at a concentration of 2 mg/ml, proving this scaffold is hemocompatible. Furthermore, an MTT assay was utilized to assess the cytotoxicity of the synthesized magnetic nanocomposite. Finally, the hyperthermia behavior of the fabricated magnetic nanocomposite was evaluated, and the specific absorption rate (SAR) was 73.53 W/g. The proposed nanocomposite is a good candidate for wound dressing applications in future studies.


Assuntos
Fibroínas , Hipertermia Induzida , Nanocompostos , Hidrogéis , Alginatos , Espectroscopia de Infravermelho com Transformada de Fourier , Fenômenos Magnéticos
12.
BMC Biotechnol ; 22(1): 31, 2022 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-36307814

RESUMO

BACKGROUND: Staphylococcal superantigens are virulence factors that help the pathogen escape the immune system and develop an infection. Toxic shock syndrome toxin (TSST)-1 is one of the most studied superantigens whose role in toxic shock syndrome and some particular disorders have been demonstrated. Inhibiting TSST-1 production with antibiotics and targeting TSST-1 with monoclonal antibodies might be one of the best strategies to prevent TSST-1-induced cytokines storm followed by lethality. RESULTS: A novel single-chain variable fragment (scFv), MS473, against TSST-1 was identified by selecting an scFv phage library on the TSST-1 protein. The MS473 scFv showed high affinity and specificity for TSST-1. Moreover, MS473 could significantly prevent TSST-1-induced mitogenicity (the IC50 value: 1.5 µM) and cytokine production. CONCLUSION: Using traditional antibiotics with an anti-TSST-1 scFv as a safe and effective agent leads to deleting the infection source and preventing the detrimental effects of the toxin disseminated into the whole body.


Assuntos
Anticorpos de Cadeia Única , Humanos , Anticorpos de Cadeia Única/farmacologia , Anticorpos de Cadeia Única/metabolismo , Staphylococcus aureus , Superantígenos/metabolismo , Superantígenos/farmacologia , Enterotoxinas , Citocinas/metabolismo , Antibacterianos/farmacologia
13.
AMB Express ; 12(1): 124, 2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36138332

RESUMO

Design of experiment (DOE) is a statistical approach for designing, performing, and interpreting a large set of data with the minimum number of tests. In our previous study, we developed a novel Hsp27 SILEX system for production of recombinant proteins. In the present study, we optimized indirectly the most effective factors including inoculation load, self-induction temperature, and culture media on autoinduction of staphylokinase (SAK) expression using RSM methodology and fluorometry. The expression level of SAK was assayed at different runs after 6 h incubation at 90 rpm. The results indicated all parameters significantly affect the SAK expression level (p < 0.05). The optimum expression condition was obtained with an inoculation load of 0.05, a temperature of 25 °C, and TB culture medium. The analysis of variance with a R2 value of 0.91 showed that a quadratic model well described this prediction (p < 0.05). Applying the optimized condition led to an approximately fourfold increase in the SAK expression level (from 1.3 to 5.2 µg/ml). Moreover, the recombinant protein was purified using immobilized metal affinity chromatography and the activity was also confirmed by semi-quantitative caseinolytic method.

14.
AMB Express ; 12(1): 88, 2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35821141

RESUMO

Hyaluronic Acid (HA) is a natural biopolymer that has important physiological and industrial applications due to its viscoelastic and hydrophilic characteristics. The responsible enzyme for HA production is Hyaluronan synthase (HAS). Although in vitro structure-function of intact HAS enzyme has been partly identified, there is no data on in vivo function of truncated HAS forms. In the current study, novel recombinant Bacillus subtilis strains harboring full length (RBSFA) and truncated forms of SeHAS (RBSTr4 and RBSTr3) were developed and HA production was studied in terms of titer, production rate and molecular weight (Mw). The maximum HA titer for RBSFA, RBSTr4 and RBSTr3 was 602 ± 16.6, 503 ± 19.4 and 728 ± 22.9 mg/L, respectively. Also, the HA production rate was 20.02, 15.90 and 24.42 mg/L.h-1, respectively. The findings revealed that RBSTr3 produced 121% and 137% more HA rather than RBSFA and RBSTr4, respectively. More interestingly, the HA Mw was about 60 kDa for all strains which is much smaller than those obtained in prior studies.

15.
Int J Biol Macromol ; 217: 1-18, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-35809676

RESUMO

There is a growing demand for biomaterials developing with novel properties for biomedical applications hence, hydrogels with 3D crosslinked polymeric structures obtained from natural polymers have been deeply inspected in this field. Pectin a unique biopolymer found in the cell walls of fruits and vegetables is extensively used in the pharmaceutical, food, and textile industries due to its ability to form a thick gel-like solution. Considering biocompatibility, biodegradability, easy gelling capability, and facile manipulation of pectin-based biomaterials; they have been thoroughly investigated for various potential biomedical applications including drug delivery, wound healing, tissue engineering, creation of implantable devices, and skin-care products.


Assuntos
Materiais Biocompatíveis , Pectinas , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Sistemas de Liberação de Medicamentos , Hidrogéis/química , Pectinas/química , Polímeros , Engenharia Tecidual
16.
Arch Microbiol ; 204(6): 343, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35596084

RESUMO

Cold atmospheric plasma (CAP) is being used recently as a modern technique for microbial random mutagenesis. In the present study, CAP was used to induce mutagenesis in L. enzymogenes which is the bacteria known for producing proteolytic enzymes especially lysyl endopeptidase (Lys C). Enhanced proteolytic activity was the main criteria to select mutant strains. Therefore, the cell suspension of L. enzymogenes strain (ATCC 29487), was exposed to CAP for 30, 45, 90, and 150 s. The proteolytic activity of mutant strains was screened initially by radial caseinolytic assay and then by Ansons method in different phases of bacterial growth in the selected mutants. The purification process of Lysyl endopeptidase as the target enzyme was optimized and for enlightening molecular aspect of CAP mutagenesis, the sequences of the upstream and coding regions of lys C gene from 10 selected mutant strains were determined. The bacterial survival assessment showed that the more CAP treatment time, the less survival rate, however, in all exposure times, a number of survived mutants showed enhanced proteolytic activity. Among 38 out of 100 examined mutants which showed higher proteolytic activity than that of wild type, the M1-30 s mutant exhibited the highest increment to 1.94 fold. The SDS-PAGE analysis showed expected size of purified Lys C from M1-30 s. The Lys C gene from M14-150 s mutant strain (1.4-fold increment) harbored three point mutations which can be effective in enhancing protease activity. In conclusion, the results highlighted the role of CAP for strain improvement process to obtain industrial strains.


Assuntos
Lysobacter , Gases em Plasma , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Lysobacter/genética , Lysobacter/metabolismo , Gases em Plasma/metabolismo , Gases em Plasma/farmacologia
17.
Clin Lab ; 68(4)2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35443593

RESUMO

BACKGROUND: Hepatitis B virus surface antigen (HBsAg) is an important protein in both diagnosis and prevention of hepatitis B infection. In the current study, a piezoelectric immunosensor based on antibody-antigen interaction was designed to detect HBsAg. A quartz crystal microbalance system was employed to detect antibody-antigen interaction. METHODS: At first, an oscillator was designed to measure the resonant frequency affected by the reactants using IC 74LVC1GX04. Antibody against HBsAg was immobilized on 10 MHz AT-cut quartz crystal. The surface modifications were monitored by atomic force microscopy (AFM) and contact angle measurements. Different concentrations of antibody were used for surface immobilization and the frequency shifts were assessed. The system stability was studied by evaluating the stability of the crystal and the immobilized antibody. The adsorption of antibody onto the crystal was analyzed using AFM and changes in the resonance frequency. Further, a direct immunoassay was performed with this immobilized antibody to identify HBsAg solutions at different concentrations. Finally, specific and non-specific responses were investigated using hepatitis B (HBsAg) and hepatitis C (HCV Ag) antigens, respectively. RESULTS: Antibodies against HBsAg were successfully immobilized on 10 MHz AT-cut quartz crystal. The stability tests of crystal immobilized with antibody and unimmobilized crystal revealed that both forms of crystals were stable. Theoretical and experimental frequency assays were compared. A decrease in the contact angle indicated the hydrophilicity of surface after modifications. AFM images illustrated a more uniform surface after antibody adsorption and the surface roughness (RMS) reduced from 1.13 to 0.99 nm. Changes in the frequency were detected after the physical adsorption of HBsAb on the designed chip. The standard curve of antigen revealed the frequency changes depend on concentration of antigen. Finally, the specificity test confirmed the specificity of the designed biosensor for the detection of HBsAg from HCV Ag. The quantization of immobilized antibody was characterized by the frequency shift of the QCM. The obtained results were compared with ELISA assay. The correlation coefficients of HBsAg dilution between QCM and ELISA was 0.9821. CONCLUSIONS: This study is a new step to meet the challenges regarding HBsAg detection. Physical adsorption used in this study was effective as the simplest immobilization method to design a QCM-based immunosensor for HBsAg detection. Facilitated, fast, and simple detection of HBsAg by an antibody-based QCM biosensor is our main objective.


Assuntos
Técnicas Biossensoriais , Hepatite B , Hepatite C , Técnicas Biossensoriais/métodos , Hepatite B/diagnóstico , Anticorpos Anti-Hepatite B , Antígenos de Superfície da Hepatite B , Humanos , Imunoensaio/métodos , Quartzo
18.
Mol Biol Rep ; 49(5): 3389-3399, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35389131

RESUMO

BACKGROUND: Aberrant expression of long non-coding RNAs (lncRNAs) can contribute to the pathogenesis of coronary artery disease (CAD). In this study, we aimed to evaluate the expression of lncRNA interferon γ-antisense 1 (IFNG-AS1), zinc finger E-box binding homeobox 2 antisense RNA 1 (ZEB2-AS1), and their direct target genes (IFN-γ and ZEB2, respectively) in peripheral blood mononuclear cell (PBMC) from CAD and healthy individuals. METHODS AND RESULTS: We recruited 40 CAD patients and 40 healthy individuals. After doing some bioinformatics analyses, the expressions of IFNG-AS1/ ZEB2-AS1 lncRNAs and IFN-γ/ ZEB2 in PBMCs were measured using quantitative real-time PCR. The possible correlation between the putative lncRNAs and disease severity was also assessed. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive role of lncRNAs as diagnostic biomarkers in CAD patients. The expressions of IFNG-AS1 lncRNA as well as IFN-γ and ZEB2 genes were significantly reduced in CAD patients compared to healthy subjects. In contrast, the expression of ZEB2-AS1 was up-regulated in these patients. Linear regression analysis unveiled that there is a positive correlation between the expression of IFNG-AS1 and IFN-γ, also similarly, ZEB2-AS1 and ZEB2 in PBMCs of subjects. Moreover, the expression of IFNG-AS1 and ZEB2-AS1 correlated with the Gensini score. The area under the ROC curves ranged from 0.633-0.742 for ZEB2-AS1/ZEB2 and IFNG-AS1/IFN-γ, respectively. CONCLUSIONS: Our results indicated that the dysregulation of IFNG-AS1/IFN-γ and ZEB2-AS1/ZEB2 in PBMCs of CAD patients may be involved in CAD pathogenesis.


Assuntos
Doença da Artéria Coronariana , Interferon gama/genética , RNA Longo não Codificante , Homeobox 2 de Ligação a E-box com Dedos de Zinco/genética , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/metabolismo , Humanos , Interferon gama/metabolismo , Leucócitos Mononucleares/metabolismo , RNA Longo não Codificante/metabolismo , Homeobox 2 de Ligação a E-box com Dedos de Zinco/metabolismo
19.
Int Immunopharmacol ; 105: 108585, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35131732

RESUMO

Solid cancers are affiliate on angiogenesis for preservation. The FDA-approved monoclonal antibodies like Bevacizumab are currently being administered effectively as inhibitors of angiogenesis against various types of tumors. Despite the clinical achievements in this regard, monoclonal antibodies suffer from considerable disadvantages, including the potential to develop therapeutic resistance, a high production cost, and the restricted tumor penetration, which consequently limit their therapeutic applications. In the past decades, some significant methods such as miniaturization of the antibodies, containing those inhibiting tumor angiogenesis, have been proposed to enhance cancer therapeutics efficiency. Since their discovery, small single-domain antigen binding antibody fragments, known as nanobodies, have been broadly utilized in the fields of cancer research, diagnosis, and treatment. Due to their desired functional attributes and a unique structure, nanobodies are becoming promising therapeutic and diagnostic biomolecules in oncology field. Moreover, they displayed a substantial translational potential in preclinical and clinical studies. This review was performed with the aim of highlighting the potential of nanobodies in blocking the angiogenic process by targeting of angiogenic biomolecules for cancer therapy and the application of labeled nanobodies in non-invasive in vivo tumor imaging.


Assuntos
Antineoplásicos Imunológicos , Neoplasias , Anticorpos de Domínio Único , Antineoplásicos Imunológicos/uso terapêutico , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Anticorpos de Domínio Único/uso terapêutico
20.
World J Microbiol Biotechnol ; 38(1): 17, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34897561

RESUMO

Serratiopeptidase is a bacterial protease that has been used medicinally in variety of applications. Though, some drawbacks like sensitivity to environmental conditions and low penetration into cells limited its usage as a potent pharmaceutical agent. This study aimed to produce four novel truncated serratiopeptidase analogs with different lengths and possessing one disulfide bridge, in order to enhance protease activity and thermal stability of this enzyme. Mutagenesis and truncation were performed using specific primers by conventional and overlap PCR. The recombinant proteins were expressed in E. coli cells then purified and their protease activity and stability were checked at different pH and temperatures in comparison to the native form of the enzyme, Serra473. Enzyme activity assay showed that T306 [12-302 ss] was not further active which could be due to the large truncation. However, T344 [8-339 ss], T380 [8-339 ss] and T380 [12-302 ss] proteins showed higher proteolytic activity comparing to Serra473. These analogs were active at temperatures of 25-90 °C and pH 6-9.5. Interestingly, remaining enzyme activity of T344 [8-339 ss], T380 [8-339 ss] and T380 [12-302 ss] forms at 90 °C calculated as 87, 83 and 86 percent, respectively, comparing to the activity at room temperature. However, residual activity at the same conditions was 50% for the full length enzyme. Formation of disulfide bond in engineered serratiopeptidases could be the main reason for higher thermal stability compared to Serra473. Thermostability of T344 [8-339 ss], as the most thermostable designed serratiopeptidase, was additionally confirmed using differential scanning calorimetry.


Assuntos
Estabilidade Enzimática , Escherichia coli/metabolismo , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Engenharia Genética , Concentração de Íons de Hidrogênio , Microbiologia Industrial , Mutagênese Sítio-Dirigida , Proteólise , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...