Next-generation viral nanoparticles for targeted delivery of therapeutics: Fundamentals, methods, biomedical applications, and challenges.

INTRODUCTION: Viral nanoparticles (VNPs) are virus-based nanocarriers that have been studied extensively and intensively for biomedical applications. However, their clinical translation is relatively low compared to the predominating lipid-based nanoparticles. Therefore, this article describes the fundamentals, challenges, and solutions of the VNP-based platform, which will leverage the development of next-generation VNPs. AREAS COVERED: Different types of VNPs and their biomedical applications are reviewed comprehensively. Strategies and approaches for cargo loading and targeted delivery of VNPs are examined thoroughly. The latest developments in controlled release of cargoes from VNPs and their mechanisms are highlighted too. The challenges faced by VNPs in biomedical applications are identified, and solutions are provided to overcome them. EXPERT OPINION: In the development of next-generation VNPs for gene therapy, bioimaging and therapeutic deliveries, focus must be given to reduce their immunogenicity, and increase their stability in the circulatory system. Modular virus-like particles (VLPs) which are produced separately from their cargoes or ligands before all the components are coupled can speed up clinical trials and commercialization. In addition, removal of contaminants from VNPs, cargo delivery across the blood brain barrier (BBB), and targeting of VNPs to organelles intracellularly are challenges that will preoccupy researchers in this decade.

Essential oils and plant extracts for tropical fruits protection: From farm to table.

The tropical fruit industry in Malaysia makes up a large proportion of the agriculture sector, contributing to the local economy. Due to their high sugar and water content, tropical fruits are prone to pathogenic infections, providing optimal microorganism growth conditions. As one of the largest exporters of these fruits globally, following other Southeast Asian countries such as Thailand, Indonesia and the Philippines, the quality control of exported goods is of great interest to farmers and entrepreneurs. Traditional methods of managing diseases in fruits depend on chemical pesticides, which have attracted much negative perception due to their questionable safety. Therefore, the use of natural products as organic pesticides has been considered a generally safer alternative. The extracts of aromatic plants, known as essential oils or plant extracts, have garnered much interest, especially in Asian regions, due to their historical use in traditional medicine. In addition, the presence of antimicrobial compounds further advocates the assessment of these extracts for use in crop disease prevention and control. Herein, we reviewed the current developments and understanding of the use of essential oils and plant extracts in crop disease management, mainly focusing on tropical fruits. Studies reviewed suggest that essential oils and plant extracts can be effective at preventing fungal and bacterial infections, as well as controlling crop disease progression at the pre and postharvest stages of the tropical fruit supply chain. Positive results from edible coatings and as juice preservatives formulated with essential oils and plant extracts also point towards the potential for commercial use in the industry as more chemically safe and environmentally friendly biopesticides.

Preliminary study on designing the binder of sperm-1 synthetic vaccine using sequence-based methods and molecular docking.

Objective: The main objective of this study is to design a synthetic vaccine from the binder of sperm-1 (BSP1). Materials and Methods: This study was carried out using bioinformatics-related techniques. BSP-1 has been chosen as one of the biomarkers of a ruminant's male fertility. We hypothesize that the BSP1 synthetic vaccines, which contain T-cell epitopes, can produce antibodies more effectively for the development of a sperm fertility detection kit. A sequence of BSP-1 peptides A0A0K1YXR5 from Bubalus bubalis (Domestic water buffalo) origin has been decided to be used to develop the peptide vaccine. Results: In this study, we succeeded in making synthetic vaccines from BSP-1 with a peptide sequence of LPEDSVPDEERVFPFTYRNRKHF. The three-dimensional theoretical prediction analysis of the peptide binding pattern to its ligand, as well as the molecular docking, has also been revealed. Conclusions: A synthetic vaccine from the BSP-1 has been developed in this study with the amino acid sequence LPEDSVPDEERVFPFTYRNRKHF, which is buffer-soluble, and the three-dimensional theoretical prediction analysis of the peptide binding pattern of BSP-1 to its ligand, as well as molecular docking, has also been revealed.

Transcatheter Closure of Perimembranous Ventricular Septal Defect Using the Lifetech Konar-Multi Functional Occluder: Early to Midterm Results of the Indonesian Multicenter Study.

Background: The alternative device to close perimembranous ventricular septal defect (pmVSD) has been searched for better result, less complications and applicable for infants. However, the ideal device is still unavailable. We aimed to evaluate the effectiveness and outcome of transcatheter pmVSD closure using the KONAR-multi functional occluder (MFO). Methods: Clinical, procedural, follow-up data of pmVSD patients with symptom of heart failure or evidence of significant left to right shunt, growth failure, recurrent respiratory tract infection, and history of endocarditis who underwent transcatheter closure using the MFO were prospectively evaluated. Results: Between January 2016 and December 2017, there were complete records of 132 pmVSD children closed using MFO from eleven centers in Indonesia. The median of age was 4.5 (0.3-17.4) years; weight 14.8 (3.5-57) kg, defect size at the smallest part 3.4 (1.0-8.1) mm, flow ratio 1.6 (1.3-4.9), mean pulmonary artery pressure 18 (7-79) mmHg, fluoroscopy time 18 (3.8-91) and procedural time 75 (26-290) minutes. A retrograde approach was done in 41 (31%) patients. Procedures succeeded in first attempt in 126 (95.4%), failed in three and migration in three patients. Six of eight infants with congestive heart failure were closed successfully. Of 126 patients with successful VSD closure, 12 months follow-up were completed in all patients. The rate of complete occlusion at 1 month, 3 months, 6 months and 12 months after intervention were 95.2%, 97.6%, 99.2%, and 99.2%, respectively. New-onset aortic regurgitation and moderate tricuspid regurgitation developed only in five and three patients. Neither complete atrioventricular block, nor other complications occurred. Conclusion: Transcatheter closure of pmVSD using the MFO is safe, effective, and feasible in infants and children.

Detection of koi herpesvirus in healthy common carps, Cyprinus carpio L.

Koi herpesvirus (KHV), a member of Hervesviridae, has been frequently reported to cause mass mortality (80-100%) in common carps (Cyprinus carpio L.). A unique feature of Herverviridae members is latent infection, maintaining their genetic information for an extended period in the absence of productive infection, and reactivate when environmental conditions are favorable for their growth. To prevent this occurs, a monitoring program should be done for early detection. This study aimed at detecting the presence of KHV in healthy common carps reared in West-Nusa Tenggara Province, Indonesia. A total of 80 healthy fish was collected randomly from eight fish farms (Lingsar, Batu Kumbung, Narmada, Tanjung, Lenek, Aik Mel, Brang Rea and Rhee) across West-Nusa Tenggara Province, Indonesia. The presence of KHV genome was detected using a PCR with a commercial kit, IQ 2000TM. The result showed that common carps collected from four farms (Aik Mel, Lenek, Rhee and Brang Rea) were positive KHV. The size of an amplified gene was ~ 550 bp which was the same as positive KHV control. The obtained result suggests that KHV as other member of Hervesviridae shows a latent infection in common carps, and should be anticipated for their reactivation. Based on this result it is highly recommended that common carps cultured in this region should be vaccinated. In addition, transporting common carp out from Lombok and Sumbawa Islands should be carefully regulated to prevent the spread of the disease to other areas.

Sequence Diversity of pfmdr1 and Sequence Conserve of pldh in Plasmodium falciparum from Indonesia: Its implications on Designing a Novel Antimalarial Drug with Less Prone to Resistance.

BACKGROUND: pfmdr1 and its variants are molecular marker which are responsible for antibiotics resistance in Plasmodium falciparum, a parasitic carrier for malaria disease. A novel strategy to treat malaria disease is by disrupting parasite lactate dehydrogenase (pLDH), a crucial enzyme for Plasmodium survival during their erythrocytic stages. This research was aimed to investigate and characterize the pfmdr1 and pldh genes of P. falciparum isolated from Nusa Tenggara Indonesia. METHODS: Genomic DNA of P.falciparum was isolated from malaria patients in Nusa Tenggara Indonesia. pfmdr1 was amplified using nested PCR and genotyped using Restriction Fragment Length Polymorphism (RFLP). pldh was amplified, sequenced, and analyzed using NCBI public domain databases and alignment using Clustal W ver. 1.83. RESULTS: Genotyping of the pfmdr1 revealed that sequence diversity was extremely high among isolates. However, a sequence analysis of pldh indicated that open reading frame of 316 amino acids of the gene showing 100% homology to the P. falciparum 3D7 reference pldh (GeneBank: XM_001349953.1). CONCLUSION: This is the first report which confirms the heterologous of pfmdr1 and the homologous sequences of P.falciparum pldh isolated from Nusa Tenggara Islands of Indonesia, indicating that the chloroquine could not be used effectively as antimalarial target in the region and the pLDH-targeted antimalarial compound would have higher chance to be successful than using chloroquine for curbing malaria worldwide.

In vitro generation of anti-hepatitis B monoclonal antibodies from a single plasma cell using single-cell RT-PCR and cell-free protein synthesis.

Monoclonal antibodies (mAbs) are an effective tool in therapeutics and diagnostics. A novel approach called the single-cell RT-PCR-linked in vitro expression system (SICREX) enables the high-throughput generation and screening of mAbs from single B cells. In this paper, instead of using B cells, cDNAs were synthesized from single plasma cells of an immunized mouse spleen. The light chain (Lc) and the Fd portion of the heavy chain (Hc) genes of each cell were amplified separately and followed by overlapping PCR to add a T7 promoter, a ribosome-binding site, and a T7 terminator. The paired Lc and Hc genes were simultaneously expressed by an Escherichia coli in vitro transcription and translation system followed by ELISA to measure their affinity for the antigen. A Fab fragment with affinity against the antigen was obtained from plasma cells of an immunized mouse with hepatitis B surface antigen (HBsAg).

Antimicrobial and cytotoxic activities of Malaysian endophytes.

Endophytes, which are receiving increasing attention, have been found to be potential sources of bioactive metabolites following the discovery of paclitaxel producing endophytic fungi. In the present study, a total of 348 endophytes were isolated from different parts of 24 Malaysian medicinal plants. Three selected endophytes (HAB10R12, HAB11R3 and HAB21F25) were investigated for their antimicrobial and cytotoxic activities. For antimicrobial activity, HAB10R12 and HAB11R3 were found to be most active against bacteria and fungi, respectively. Their antimicrobial effects were comparable to, if not better than, a number of current commercial antibacterial and antifungal agents. Both HAB10R12 and HAB21F25 were found to be potential anticancer drug candidates, having potent activity against MCF-7 and HCT116 cell lines and warrant further investigation.

Generation of monoclonal antibodies using simplified single-cell reverse transcription-polymerase chain reaction and cell-free protein synthesis.

The single-step PCR amplification of IgG Light chain (Lc) and Heavy chain (Hc) (Fd portion) from the cDNAs of a single cell was facilitated using a low concentration of cDNA-specific primers with 5' homotags in the presence of a homotag-specific primer. This method was found to be successful in generating a functional antibody with an antigen-binding activity and useful for the high-throughput generation or screening of monoclonal antibodies.

Improvements in the cell-free production of functional antibodies using cell extract from protease-deficient Escherichia coli mutant.

Expression of a functional antibody fragment (Fab) using an Escherichia coli cell-free expression system has been reported previously [Jiang et al., FEBS Lett., 514, 290-294 (2002)]. The low yield of the synthesized antibody, however, limits the usefulness of the cell-free expression system, partly due to the degradation of product by endogenous proteases from the E. coli extract. To determine which proteases are responsible for the degradation, we compared the expression of a 6D9 Fab fragment under conditions whereby several protease inhibitors were added into the cell-free system. The addition of serine protease inhibitor increased the amount of the Fab fragment, indicating that serine proteases caused the antibody degradation. Therefore, several serine protease-deficient mutants of E. coli BW25113 were constructed by targeted homologous recombination. The use of extract from a double protease-deficient mutant (DeltadegP-ompT) significantly increased the amount and antigen-binding activities of an anti-HSA scFv and a 6D9 Fab fragment. These results suggest that the DegP- and OmpT-deleted mutant is a useful source of S30 extract for the production or screening of antibodies using the cell-free expression system.