Novel one step transformation method for Escherichia coli and Staphylococcus aureus using arginine-glucose functionalized hydroxyapatite nanoparticles

An Optimized Transformation Protocol for Escherichia coli BW3KD with Supreme DNA Assembly Efficiency

DNA cloning requires two steps: the assembly of recombinant DNA molecules and the transformation of the product into a host organism for replication. High efficiencies in both processes can increase the success rate. Recently, we developed an Escherichia coli BW3KD strain with higher transformation efficiency than commonly used cloning strains. Here, we further developed a simple method named TSS-HI (transformation storage solution optimized by Hannahan and Inoue method) for competent cell preparation, which combined the advantages of three common methods for operational simplicity and high transformation efficiency. When competent BW3KD cells were prepared using this developed method, the transformation efficiency reached up to (7.21 ± 1.85) × 10⁹ CFU/μg DNA, which exceeded the levels of commercial chemically competent cells and homemade electrocompetent cells. BW3KD cells formed colonies within 7 h on lysogeny broth agar plates, quicker than the well-known fast-growing E. coli cloning strain Mach1. The competent cells worked effectively for the transformation of assembled DNA of 1 to 7 fragments in one step and promoted efficiencies of transformation or cloning with large plasmids. The cloning efficiency of BW3KD cells prepared by this method increased up to 828-fold over that of E. coli XL1-Blue MRF' cells prepared by a common method. Thus, competent cells are suitable for different cloning jobs and should help with the increased demand for DNA assembly in biological studies and biotechnology. IMPORTANCE DNA transformation is commonly used in cloning; however, high transformation efficiency becomes a limiting factor in many applications, such as the construction of CRISPR and DNA libraries, the assembly of multiple fragments, and the transformation of large plasmids. We developed a new competent cell preparation method with unmatched transformation efficiency. When the BW3KD strain, derived from Escherichia coli BW25113 cells, was prepared by this method, its transformation efficiency reached up to (7.21 ± 1.85) × 10⁹ CFU/μg DNA, which broke the record for chemically prepared competent cells. Routine cloning could be completed in 1 day due to the high growth rate of this strain. The competent cells were shown to be highly efficient for transformation or cloning with large plasmids and for the assembly of multiple fragments. The results highlight the effectiveness of the new protocol and the usefulness of the BW3KD strain as the host.

Microorganisms-An Effective Tool to Intensify the Utilization of Sulforaphane

Sulforaphane (SFN) was generated by the hydrolysis of glucoraphanin under the action of myrosinase. However, due to the instability of SFN, the bioavailability of SFN was limited. Meanwhile, the gut flora obtained the ability to synthesize myrosinase and glucoraphanin, which could be converted into SFN in the intestine. However, the ability of microorganisms to synthesize myrosinase in the gut was limited. Therefore, microorganisms with myrosinase synthesis ability need to be supplemented. With the development of research, microorganisms with high levels of myrosinase synthesis could be obtained by artificial selection and gene modification. Researchers found the SFN production rate of the transformed microorganisms could be significantly improved. However, despite applying transformation technology and regulating nutrients to microorganisms, it still could not provide the best efficiency during generating SFN and could not accomplish colonization in the intestine. Due to the great effect of microencapsulation on improving the colonization ability of microorganisms, microencapsulation is currently an important way to deliver microorganisms into the gut. This article mainly analyzed the possibility of obtaining SFN-producing microorganisms through gene modification and delivering them to the gut via microencapsulation to improve the utilization rate of SFN. It could provide a theoretical basis for expanding the application scope of SFN.

Self-fluorescence property of octa-arginine functionalized hydroxyapatite nanoparticles aids in studying their intracellular fate in R1 ESCs

Deciphering the endocytosis mechanisms of nanoparticle entry in cells is crucial to understand the fate of nanoparticles and the biological activity of the transported cargo. Such studies require the use of reporter agents such as fluorescent markers. Previously, we have reported the synthesis of self-fluorescent HAp nanoparticles as efficient nucleic acid delivery agents in prokaryotic and eukaryotic cells. Here, we show the application of biocompatible self-fluorescent nano delivery vehicle based on HAp and CPP- octa-arginine as an efficient system to study the mechanisms of intracellular fate of a gene delivery agent. The pathway of octa-arginine functionalized HAp NP (R8HNP) and HAp NP uptake in R1 ESCs was elucidated using confocal microscopy with the help of endocytic inhibitors. The NPs mainly enter R1 ESCs by clathrin mediated and macropinocytosis pathways. It was established that the NPs escape endosomal degradation by proton sponge effect owing to their ability to buffer the pH and trigger osmotic rupture. The functionalization of CPP, effectively enhanced the internalization and endosomal escape in R1 ESCs. The detailed results of these studies are outlined in this manuscript.

Synthesis, Characterization, Functionalization and Bio-Applications of Hydroxyapatite Nanomaterials: An Overview

Hydroxyapatite (HA) is similar to natural bone regarding composition, and its structure favors in biomedical applications. Continuous research and progress on HA nanomaterials (HA-NMs) have explored novel fabrication approaches coupled with functionalization and characterization methods. These nanomaterials have a significant role in many biomedical areas like sustained drug and gene delivery, bio-imaging, magnetic resonance, cell separation, and hyperthermia treatment due to their promising biocompatibility. This review highlighted the HA-NMs chemical composition, recent progress in synthesis methods, characterization and surface modification methods, ion-doping, and role in biomedical applications. HA-NMs have a substantial role as drug delivery vehicles, coating material, bone implant, coating, ceramic, and composite materials. Here, we try to summarize an overview of HA-NMs with the provision of future directions.

A nano-biomimetic transformation system enables in planta expression of a reporter gene in mature plants and seeds

Plant genetic engineering will be essential to decipher the genomic basis of complex traits, optimize crop genomics, and enable plant-based production of recombinant proteins. However, established plant transformation approaches for bioengineering are fraught with limitations. Although nanoparticle-mediated methods show great promise for advancing plant biotechnology, many engineered nanomaterials can have cytotoxic and ecological effects. Here, we demonstrate the efficient uptake of a nano-biomimetic carrier of plasmid DNA and transient expression of a reporter gene in leaves of Arabidopsis, common ice plant and tobacco, as well as in the developing seed tissues of Arabidopsis, field mustard, barley, and wheat. The nano-biomimetic transformation system described here has all the advantages of other nanoparticle-mediated approaches for passive delivery of genetic cargo into a variety of plant species and is also nontoxic to cells and to the environment for diverse biotechnological applications in plant biology and crop science.

Nanocarrier Mediated siRNA Delivery Targeting Stem Cell Differentiation

Stem cell-based regenerative medicine holds exceptional therapeutic potential and hence the development of efficient techniques to enhance control over the rate of differentiation has been the focus of active research. One of the strategies to achieve this involves delivering siRNA into stem cells and exploiting the RNA interference (RNAi) mechanism. Transport of siRNA across the cell membrane is a challenge due to its anionic property, especially in primary human cells and stem cells. Moreover, naked siRNA incites immune responses, may cause off-target effects, exhibits low stability and is easily degraded by endonucleases in the bloodstream. Although siRNA delivery using viral vectors and electroporation has been used in stem cells, these methods demonstrate low transfection efficiency, cytotoxicity, immunogenicity, events of integration and may involve laborious customization. With the advent of nanotechnology, nanocarriers which act as novel gene delivery vehicles designed to overcome the problems associated with safety and practicality are being developed. The various nanomaterials that are currently being explored and discussed in this review include liposomes, carbon nanotubes, quantum dots, protein and peptide nanocarriers, magnetic nanoparticles, polymeric nanoparticles, etc. These nanodelivery agents exhibit advantages such as low immunogenic response, biocompatibility, design flexibility allowing for surface modification and functionalization, and control over the surface topography for achieving the desired rate of siRNA delivery and improved gene knockdown efficiency. This review also includes discussion on siRNA co-delivery with imaging agents, plasmid DNA, drugs etc. to achieve combined diagnostic and enhanced therapeutic functionality, both for in vitro and in vivo applications.

Abiotic Factors Promote Cell Penetrating Peptide Permeability in Enterobacteriaceae Models

Conventionally, the delivery of biomolecules into bacteria for the generation of characterized or functional mutants has relied greatly on horizontal gene transfer techniques. However, the low compatibility of these techniques with novel or hard-to-transform bacteria currently serves as a challenge to the bioengineering field. Here, we explored the use of cell penetrating peptides (CPPs) as an alternative biomolecule delivery approach by investigating the effects of the abiotic factors during CPP permeation. Using the (KFF)₃K-FAM conjugate and Escherichia coli as models, we evaluated four abiotic factors where two of these factors, temperature and solution tonicity, promoted (KFF)₃K-FAM permeation efficiency. Our data show that optimal (KFF)₃K-FAM permeation efficiency was achieved for E. coli at approximately 98.1% under conditions of 37°C (growth optimal temperature) and 50% PBS concentration. Based on these conditions, we subsequently tested the applicability of CPP permeation in various bacterial strains by treating 10 bacterial strains from the Enterobacteriaceae family among which seven strains have no CPP permeation records with (KFF)₃K-FAM. Interestingly, when compared with non-optimized conditions, all 10 strains showed a marked increase in CPP permeation ranging between 20 and 90% efficiency. Although using strains within Enterobacteriaceae that are phylogenetically close, our results hinted on the possibility that with proper optimization of the abiotic factors, CPPs could be compatible with a broad range of bacterial strains. Our efforts suggest that CPP could serve as an effective alternative approach for mutant generation and for biomolecule delivery into novel or hard-to-transform bacteria.

Functionalized calcium orthophosphates (CaPO4) and their biomedical applications

Due to the chemical similarity to natural calcified tissues (bones and teeth) of mammals, calcium orthophosphates (abbreviated as CaPO₄) appear to be good biomaterials for creation of artificial bone grafts. However, CaPO₄ alone have some restrictions, which limit their biomedical applications. Various ways have been developed to improve the properties of CaPO₄ and their functionalization is one of them. Namely, since surfaces always form the interfaces between implanted grafts and surrounding tissues, the state of CaPO₄ surfaces plays a crucial role in the survival of bone grafts. Although the biomedically relevant CaPO₄ possess the required biocompatible properties, some of their properties could be better. For example, functionalization of CaPO₄ to enhance cell attachment and cell material interactions has been developed. In addition, to prepare stable formulations from nanodimensional CaPO₄ particles and prevent them from agglomerating, the surfaces of CaPO₄ particles are often functionalized by sorption of special chemicals. Furthermore, there are functionalizations in which CaPO₄ are exposed to various types of physical treatments. This review summarizes the available knowledge on CaPO₄ functionalizations and their biomedical applications.

Artificial transformation methodologies for improving the efficiency of plasmid DNA transformation and simplifying its use

The uptake of exogenous DNA materials through the cell membrane by bacteria, known as transformation, is essential for the genetic manipulation of bacteria and, thus, plays key roles in biotechnological and biological research. The efficiency of natural transformation is very low; therefore, various artificial transformation methods have been developed for simple and efficient bacterial transformation. The basic bacterial transformation method is based on chemical, physical, and electrical processes and other means to permeabilize the bacterial cell membrane to allow plasmid DNA uptake. With the introduction of novel chemicals, materials, and devices and the optimization of protocols, new transformation methods have become simpler, cheaper, and more reproducible for use in diverse bacterial species compared with conventional methods. In this review, artificial transformation methods have been classified according to the membrane-permeabilizing mechanisms employed by them. Their influential factors, transformation efficiency, advantages, disadvantages, and practical applications are briefly illustrated. Finally, physicochemical transformation as a new bacterial transformation technique has also been described.

A novel method for genetic transformation of C. albicans using modified-hydroxyapatite nanoparticles as a plasmid DNA vehicle

In modern biological research, genetic transformation is an important molecular biology technique with extensive applications. In this work, we describe a new method for the delivery of plasmid DNA (pDNA) into a yeast species, Candida albicans. This method is based on the use of novel arginine-glucose-PEG functionalized hydroxyapatite nanoparticles (M-HAp NPs) as a vehicle which delivers pDNA into Candida albicans with a high transformation efficiency of 10⁶ cfu μg^-1 of pDNA, without the need for preparation of competent cells. A four-fold higher transformation efficiency as compared to that of the electroporation method was obtained. This new method could provide exciting opportunities for the advancement of the applications of yeasts in the field of biotechnology.