Hexadecylated linear PEI self-assembled nanostructures as efficient vectors for neuronal gene delivery

Extraction, Structural Characterization, Biological Functions, and Application of Rice Bran Polysaccharides: A Review

Rice bran is a "treasure house of natural nutrition". Even so, utilization of rice bran is often ignored, and this has resulted in the wastage of nutrients. Polysaccharides are one of the active substances in rice bran that have gained widespread attention for their antioxidant, antitumor, immune-enhancing, antibacterial, and hypoglycemic properties. This review summarizes the extraction methods, structural characterization, bioactivity, and application of rice bran polysaccharides that have been developed and studied in recent years, laying a foundation for its development into foods and medicines. In addition, we also discuss the prospects for future research on rice bran polysaccharides.

Bioreducible polyethylenimine core-shell nanostructures as efficient and non-toxic gene and drug delivery vectors

Low molecular weight branched polyethylenimine (LMW bPEIs 1.8 kDa) have received considerable attention for the fabrication of nucleic acid carriers due to their biocompatible and non-toxic nature. However, due to the inadequate nucleic acid complexation ability and transportation across the cell membrane, these show poor transfection efficacy, limiting their clinical applications. Therefore, to overcome these challenges, in this study, we have grafted bPEI 1.8 kDa with a disulfide bond containing hydrophobic moiety, 3-(2-pyridyldithio) propionic acid (PDPA), via amide linkages through EDC/NHS-mediated coupling to obtain N-[3-(2-pyridyldithio)] propionoyl polyethylenimine (PDPP) conjugates. The best formulation for nucleic acid transfection was evaluated after preparing a series of PDPP conjugates by varying the amount of PDPA. In an aqueous environment, these PDPP conjugates self-assembled to form spherical shaped core-shell PDPP nanostructures with size ranging from ∼188-307 nm and zeta-potential from ∼ +3 to +19 mV. The positively charged surface of the core-shell nanocomposites helps in the binding of plasmid DNA (pDNA), its transportation inside the cell, and protection against enzymes. Evaluation of PDPP/pDNA complexes on mammalian cells revealed that all these complexes showed significantly improved transfection efficacy without hampering cytocompatibility. Amongst all, the pDNA complex of PDPP-2 exhibited the best transfection efficiency (i.e. >6-fold) in comparison to pDNA complex of the native bPEI. The nanocomposites exhibited the redox responsive behavior advantageous for therapeutic delivery to the tumor cells. The core of the nanostructures facilitate the encapsulation of a hydrophobic model drug, ornidazole. In vitro drug release analysis showed a faster release rate in response to a reductant mimicking the cellular environment. Altogether, these nanostructures have great potential to co-deliver both drug and gene simultaneously in response to tumor cell reductive microenvironment in vitro and could be used as the next-generation delivery system.

Tyrosine-modified linear PEIs for highly efficacious and biocompatible siRNA delivery in vitro and in vivo

Therapeutic gene silencing by RNA interference relies on the safe and efficient in vivo delivery of small interfering RNAs (siRNAs). Polyethylenimines are among the most studied cationic polymers for gene delivery. For several reasons including superior tolerability, small linear PEIs would be preferable over branched PEIs, but they show poor siRNA complexation. Their chemical modification for siRNA formulation has not been extensively explored so far. We generated a set of small linear PEIs bearing tyrosine modifications (LPxY), leading to substantially enhanced siRNA delivery and knockdown efficacy in vitro in various cell lines, including hard-to-transfect cells. The tyrosine-modified linear 10 kDa PEI (LP10Y) is particularly powerful, associated with favorable physicochemical properties and very high biocompatibility. Systemically administered LP10Y/siRNA complexes reveal antitumor effects in mouse xenograft and patient-derived xenograft (PDX) models, and their direct application into the brain achieves therapeutic inhibition of orthotopic glioma xenografts. LP10Y is particularly interesting for therapeutic siRNA delivery.

Formulation of a pH-sensitive cancer cell-targeted gene delivery system based on folate-chitosan conjugated nanoparticles

In this study, we investigated the design and construct of a chitosan (CA)-based targeted gene delivery system and evaluated its function. To this end, CA-folic acid/pDNA (CA-FA/pDNA) nanoparticles were prepared in different formulations using the ion gelation method. All the synthesized nanoparticles were characterized using FTIR, TEM, SEM and DLS. Moreover, the effects of molecular weight (MW) of CA, DNA, and CA concentration were inspected on encapsulation efficiency (EE). The results showed that the EE of pDNA was directly proportional with MW of CA and CA concentration but was in an inverse proportion with DNA concentration. In addition, high MW of CA and low MW of CA nanoparticles showed lower and higher pDNA release in all pH ranges, respectively. It is concluded that the N/P ratio increase can cause controlled pDNA release.

An artificial cell system for biocompatible gene delivery in cancer therapy

The gene therapy of cancer is generally recognized as a promising approach for the reversal of neoplastic progress of cancer cells. However, the lack of biocompatibility as well as highly available carriers is the bottleneck in gene therapy. In recent years, with the advances of understanding in cell signaling and cell based functions, the development of cell mimic carriers is showing great potential in evaluating the anticancer efficacy of drugs. Here in our study, an artificial cell (AC) system was fabricated to mimic the gene protection and transfection functions of cancer cells using cancer cell derived histone and membranes. As expected, the AC showed high biocompatibility as well as preferable gene transfection capability both in vitro and in vivo, and might be a promising tool for the flexible assembly of cell mimic systems in cancer therapy.

Non-Viral in Vitro Gene Delivery: It is Now Time to Set the Bar!

Transfection by means of non-viral gene delivery vectors is the cornerstone of modern gene delivery. Despite the resources poured into the development of ever more effective transfectants, improvement is still slow and limited. Of note, the performance of any gene delivery vector in vitro is strictly dependent on several experimental conditions specific to each laboratory. The lack of standard tests has thus largely contributed to the flood of inconsistent data underpinning the reproducibility crisis. A way researchers seek to address this issue is by gauging the effectiveness of newly synthesized gene delivery vectors with respect to benchmarks of seemingly well-known behavior. However, the performance of such reference molecules is also affected by the testing conditions. This survey points to non-standardized transfection settings and limited information on variables deemed relevant in this context as the major cause of such misalignments. This review provides a catalog of conditions optimized for the gold standard and internal reference, 25 kDa polyethyleneimine, that can be profitably replicated across studies for the sake of comparison. Overall, we wish to pave the way for the implementation of standardized protocols in order to make the evaluation of the effectiveness of transfectants as unbiased as possible.