Analysis of polyethylene glycol (PEG) fusion in cultured neuroblastoma cells via flow cytometry: Techniques & optimization

Current Treatments and Future Directions for Facial Paralysis

Facial palsy is a condition that affects the facial nerve, the seventh of the 12 cranial nerves. Its main function is to control the muscles of facial expression. This involves the ability to express emotion through controlling the position of the mouth, the eyebrow, nostrils, and eye closure. The facial nerve also plays a key role in maintaining the posture of the mouth and as such, people with facial paralysis often have problems with drooling, speech, and dental hygiene.Due to the devastating effects on the quality of life of individuals with facial palsy, there are a multitude of various treatment options for the paralyzed face. This article reviews current management strategies and points towards promising future directions for research in the field of facial reanimation.

Engineering aspects of lipid-based delivery systems: In vivo gene delivery, safety criteria, and translation strategies

Defects in the genome cause genetic diseases and can be treated with gene therapy. Due to the limitations encountered in gene delivery, lipid-based supramolecular colloidal materials have emerged as promising gene carrier systems. In their non-functionalized form, lipid nanoparticles often demonstrate lower transgene expression efficiency, leading to suboptimal therapeutic outcomes, specifically through reduced percentages of cells expressing the transgene. Due to chemically active substituents, the engineering of delivery systems for genetic drugs with specific chemical ligands steps forward as an innovative strategy to tackle the drawbacks and enhance their therapeutic efficacy. Despite intense investigations into functionalization strategies, the clinical outcome of such therapies still needs to be improved. Here, we highlight and comprehensively review engineering aspects for functionalizing lipid-based delivery systems and their therapeutic efficacy for developing novel genetic cargoes to provide a full snapshot of the translation from the bench to the clinics. We outline existing challenges in the delivery and internalization processes and narrate recent advances in the functionalization of lipid-based delivery systems for nucleic acids to enhance their therapeutic efficacy and safety. Moreover, we address clinical trials using these vectors to expand their clinical use and principal safety concerns.

Tyrosine-derived polymeric surfactant nanospheres insert cholesterol in cell membranes

HYPOTHESIS

The design of biodegradable tyrosine-derived polymeric surfactants (TyPS) through the use of calculated thermodynamic parameters could lead to phospholipid membrane surface modifiers capable of controlling cellular properties such as viability. Delivery of cholesterol by TyPS nanospheres into membrane phospholipid domains could provide further controlled modulation of membrane physical and biological properties.

EXPERIMENT

Calculated Hansen solubility parameters (∂_T) and hydrophile:lipophile balances (HLB) were applied to design and synthesize a small family of diblock and triblock TyPS with different hydrophobic blocks and PEG hydrophilic blocks. Self-assembled TyPS/cholesterol nanospheres were prepared in aqueous media via co-precipitation. Cholesterol loading and Langmuir film balance surface pressures of phospholipid monolayers were obtained. TyPS and TyPS/cholesterol nanosphere effects on human dermal cell viability were evaluated by cell culture using poly(ethylene glycol) (PEG) and Poloxamer 188 as controls.

FINDINGS

Stable TyPS nanospheres incorporated between 1% and 5% cholesterol. Triblock TyPS formed nanosphere with dimensions significantly smaller than diblock TyPS nanospheres. In accord calculated thermodynamic parameters, cholesterol binding increased with increasing TyPS hydrophobicity. TyPS inserted into phospholipid monolayer films in a manner consistent with their thermodynamic properties and TyPS/cholesterol nanospheres delivered cholesterol into the films. Triblock TyPS/cholesterol nanospheres increased human dermal cell viability, which was indicative of potentially beneficial TyPS effects on cell membrane surface properties.

Microfluidic Surgery in Single Cells and Multicellular Systems

Microscale surgery on single cells and small organisms has enabled major advances in fundamental biology and in engineering biological systems. Examples of applications range from wound healing and regeneration studies to the generation of hybridoma to produce monoclonal antibodies. Even today, these surgical operations are often performed manually, but they are labor intensive and lack reproducibility. Microfluidics has emerged as a powerful technology to control and manipulate cells and multicellular systems at the micro- and nanoscale with high precision. Here, we review the physical and chemical mechanisms of microscale surgery and the corresponding design principles, applications, and implementations in microfluidic systems. We consider four types of surgical operations: (1) sectioning, which splits a biological entity into multiple parts, (2) ablation, which destroys part of an entity, (3) biopsy, which extracts materials from within a living cell, and (4) fusion, which joins multiple entities into one. For each type of surgery, we summarize the motivating applications and the microfluidic devices developed. Throughout this review, we highlight existing challenges and opportunities. We hope that this review will inspire scientists and engineers to continue to explore and improve microfluidic surgical methods.

制备人脐静脉内皮细胞和人肺腺癌细胞融合细胞的新方法

Purpose:

Human umbilical endothelial cells (HUVECs) have been proved to be an effective whole-cell vaccine inhibiting tumor angiogenesis. In this study, we fused HUVECs with human lung adenocarcinoma cells A549 s, aiming at preparing lung cancer vaccine to achieve dual effects of anti-tumor angiogenesis and specific immunity to tumor cells.

Methods:

A549 cells were induced by ethyl methane sulfonate (EMS) and 8-azaguanine (8-AG) to get hypoxanthine guanine phosphoribosyl transferase (HGPRT) auxotrophic A549 cells. Then Fused HGPRT auxotrophic A549 cells with primary HUVEC cells by combining electrofusion with polyethylene glycol (PEG). Afterward the fusion cells were screened by HAT and HT selective medium and sorted by flow cell sorter to obtain high-purity HUVEC-A549 cells. Finally, HUVEC-A549 cells were identified by karyotype analysis and western blotting.

Results:

The fusion efficiency of HUVEC-A549 cells prepared by combining electrofusion with polyethylene glycol (PEG) was significantly higher than that of electrofusion and PEG (43.0% vs 17.60% vs 2.71%, P < 0.05). After screened by HAT and HT selective medium and sorted by flow cell sorter, the proportion of HUVEC-A549 cells can count for 71.2% ± 3.2%. The mode of chromosomes in HUVEC-A549 cells was 68, and the chromosome was triploid. VE-cadherin and platelet endothelial cell adhesion molecule-1 (CD31) were highly expressed in HUVECs and HUVEC-A549 cells, but not in A549 cells.

Conclusions:

These results indicate that HUVEC-A549 cells retain the biological characteristics of human umbilical vein endothelial cells and A549 cells. It can be used in the experimental study of lung cancer cell vaccine.

Melatonin Protects Rabbit Somatic Cell Nuclear Transfer (SCNT) Embryos from Electrofusion Damage

The study’s objectives were to examine the effects of electrofusion on rabbit somatic cell nuclear transfer (SCNT) embryos, and to test melatonin as a protective agent against electrofusion damage to SCNT embryos. The levels of reactive oxygen species (ROS), the epigenetic state (H3K9me3), and the content of endoplasmic reticulum (ER) stress-associated transcripts (IRE-1 and CHOP) were measured. Melatonin was added during the preimplantation development period. The total blastocyst cell numbers were counted, and the fragmentation rate and apoptotic index were determined and used to assess embryonic development. Electrofusion increased (1) ROS levels at the 1-, 2-, 4-, and 8-cell stages; (2) H3K9me3 levels at the 2-, 4-, and 8-cell stage; and (3) the expression of IRE-1 and CHOP at the 8-cell, 16-cell, morula, and blastocyst stages. The treatment of SCNT embryos with melatonin significantly reduced the level of ROS and H3K9me3, and the expression levels of IRE-1 and CHOP. This treatment also significantly reduced the fragmentation rate and apoptotic index of blastocysts and increased their total cell number. In conclusion, the electrofusion of rabbit SCNT embryos induced oxidative stress, disturbed the epigenetic state, and caused ER stress, while melatonin reduced this damage. Our findings are of signal importance for improving the efficiency of SCNT and for optimizing the application of electrical stimulation in other biomedical areas.

Bridging the gap: Spinal cord fusion as a treatment of chronic spinal cord injury

Despite decades of animal experimentation, human translation with cell grafts, conduits, and other strategies has failed to cure patients with chronic spinal cord injury (SCI). Recent data show that motor deficits due to spinal cord transection in animal models can be reversed by local application of fusogens, such as Polyethylene glycol (PEG). Results proved superior at short term over all other treatments deployed in animal studies, opening the way to human trials. In particular, removal of the injured spinal cord segment followed by PEG fusion of the two ends along with vertebral osteotomy to shorten the spine holds the promise for a cure in many cases.