Peptide-Carbon Quantum Dots conjugate, Derived from Human Retinoic Acid Receptor Responder Protein 2, against Antibiotic-Resistant Gram Positive and Gram Negative Pathogenic Bacteria

Antibiotic-resistant bacterial infections have become global issues for public health, which increases the utter need to develop alternatives to antibiotics. Here, the HSER (Homo sapiens retinoic acid receptor) peptide was designed from retinoic acid receptor responder protein 2 of Homo sapiens, and was conjugated with synthesized CQDs (carbon quantum dots) for enhanced antibacterial activity in combination, as individually they are not highly effective. The HSER-CQDs were characterized using spectrophotometer, HPLC coupled with electrospray-ionization quadrupole time-of-flight mass spectrometer (ESI-qTOF) mass spectrometer, zeta potential, zeta size, and FTIR. Thereafter, the antibacterial activity against Vancomycin-Resistant Staphylococcus aureus (VRSA) and Escherichia coli (carbapenem resistant) was studied using growth curve analysis, further supported by microscopic images showing the presence of cell debris and dead bacterial cells. The antibacterial mechanism of HSER-CQDs was observed to be via cell wall disruption and also interaction with gDNA (genomic DNA). Finally, toxicity test against normal human epithelial cells showed no toxicity, confirmed by microscopic analysis. Thus, the HSER-CQDs conjugate, having high stability and low toxicity with prominent antibacterial activity, can be used as a potential antibacterial agent.O

Extending the applicability of in ovo and ex ovo chicken chorioallantoic membrane assays to study cytostatic activity in neuroblastoma cells

Purpose The chick chorioallantoic membrane (CAM) assay can provide an alternative versatile, cost-effective, and ethically less controversial in vivo model for reliable screening of drugs. In the presented work, we demonstrate that CAM assay (in ovo and ex ovo) can be simply employed to delineate the effects of cisplatin (CDDP) and ellipticine (Elli) on neuroblastoma (Nbl) cells in terms of their growth and metastatic potential. Methods The Nbl UKF-NB-4 cell line was established from recurrent bone marrow metastases of high-risk Nbl (stage IV, MYCN amplification, 7q21 gain). Ex ovo and in ovo CAM assays were optimized to evaluate the antimetastatic activity of CDDP and Elli. Immunohistochemistry, qRT-PCR, and DNA isolation were performed. Results Ex ovo CAM assay was employed to study whether CDDP and Elli exhibit any inhibitory effects on growth of Nbl xenograft in ex ovo CAM assay. Under the optimal conditions, Elli and CDDP exhibited significant inhibition of the size of the primary tumor. To study the efficiency of CDDP and Elli to inhibit primary Nbl tumor growth, intravasation, and extravasation in the organs, we adapted the in ovo CAM assay protocol. In in ovo CAM assay, both studied compounds (CDDP and Elli) exhibited significant (p < 0.001) inhibitory activity against extravasation to all investigated organs including distal CAM. Conclusions Taken together, CAM assay could be a helpful and highly efficient in vivo approach for high-throughput screening of libraries of compounds with expected anticancer activities

Swarming Aqua Sperm Micromotors for Active Bacterial Biofilms Removal in Confined Spaces

Microscale self-propelled robots show great promise in the biomedical field and are the focus of many researchers. These tiny devices, which move and navigate by themselves, are typically based on inorganic microstructures that are not biodegradable and potentially toxic, often using toxic fuels or elaborate external energy sources, which limits their real-world applications. One potential solution to these issues is to go back to nature. Here, the authors use high-speed Aqua Sperm micromotors obtained from North African catfish (Clarias gariepinus, B. 1822) to destroy bacterial biofilm. These Aqua Sperm micromotors use water-induced dynein ATPase catalyzed adenosine triphosphate (ATP) degradation as biocompatible fuel to trigger their fast speed and snake-like undulatory locomotion that facilitate biofilm destruction in less than one minute. This efficient biofilm destruction is due to the ultra-fast velocity as well as the head size of Aqua Sperm micromotors being similar to bacteria, which facilitates their entry to and navigation within the biofilm matrix. In addition, the authors demonstrate the real-world application of Aqua Sperm micromotors by destroying biofilms that had colonized medical and laboratory tubing. The implemented system extends the biomedical application of Aqua Sperm micromotors to include hybrid robots for fertilization or cargo tasks

Characterization and in vitro analysis of probiotic-derived peptides against multi drug resistance bacterial infections

An inexorable switch from antibiotics has become a major desideratum to overcome antibiotic resistance. Bacteriocin fromLactobacillus casei, a cardinal probiotic was used to design novel antibacterial peptides named as Probiotic Bacteriocin Derived and Modified (PBDM) peptides (PBDM1: YKWFAHLIKGLC and PBDM2: YKWFRHLIKKLC). The loop-shaped 3D structure of peptides was characterizedin silicovia molecular dynamics simulation as well as biophysically via spectroscopic methods. Thereafter,in vitroresults against multidrug resistant bacterial strains and hospital samples demonstrated the strong antimicrobial activity of PBDM peptides. Further,in vivostudies with PBDM peptides showed downright recovery of balb/c mice from Vancomycin ResistantStaphylococcus aureus(VRSA) infection to its healthy condition. Thereafter,in vitrostudy with human epithelial cells showed no significant cytotoxic effects with high biocompatibility and good hemocompatibility. In conclusion, PBDM peptides displayed significant antibacterial activity against certain drug resistant bacteria which cause infections in human beings. Future analysis are required to unveil its mechanism of action in order to execute it as an alternative to antibiotics

Norepinephrine Transporter-Derived Homing Peptides Enable Rapid Endocytosis of Drug Delivery Nanovehicles into Neuroblastoma Cells

Background: Currently, the diagnosis and treatment of neuroblastomas-the most frequent solid tumors in children-exploit the norepinephrine transporter (hNET) via radiolabeled norepinephrine analogs. We aim to develop a nanomedicine-based strategy towards precision therapy by targeting hNET cell-surface protein with hNET-derived homing peptides. Results: The peptides (seq.GASNGINAYL and SLWERLAYGI) were shown to bind high-resolution homology models of hNET in silico. In particular, one unique binding site has marked the sequence and structural similarities of both peptides, while most of the contribution to the interaction was attributed to the electrostatic energy of Asn and Arg (< - 228 kJ/mol). The peptides were comprehensively characterized by computational and spectroscopic methods showing similar to 21% beta-sheets/aggregation for GASNGINAYL and similar to 27% alpha-helix for SLWERLAYGI. After decorating 12-nm ferritin-based nanovehicles with cysteinated peptides, both peptides exhibited high potential for use in actively targeted neuroblastoma nanotherapy with exceptional in vitro biocompatibility and stability, showing minor yet distinct influences of the peptides on the global expression profiles. Upon binding to hNET with fast binding kinetics, GASNGINAYLC peptides enabled rapid endocytosis of ferritins into neuroblastoma cells, leading to apoptosis due to increased selective cytotoxicity of transported payload ellipticine. Peptide-coated nanovehicles significantly showed higher levels of early apoptosis after 6 h than non-coated nanovehicles (11% and 7.3%, respectively). Furthermore, targeting with the GASNGINAYLC peptide led to significantly higher degree of late apoptosis compared to the SLW-ERLAYGIC peptide (9.3% and 4.4%, respectively). These findings were supported by increased formation of reactive oxygen species, down-regulation of survivin and Bcl-2 and up-regulated p53. Conclusion: This novel homing nanovehicle employing GASNGINAYLC peptide was shown to induce rapid endocytosis of ellipticine-loaded ferritins into neuroblastoma cells in selective fashion and with successful payload. Future homing peptide development via lead optimization and functional analysis can pave the way towards efficient peptide-based active delivery of nanomedicines to neuroblastoma cells