CRISPR-Cas9 Engineered Extracellular Vesicles for the Treatment of Dominant Progressive Hearing Loss

Clinical translation of gene therapy has been challenging, due to limitations in current delivery vehicles such as traditional viral vectors. Herein, we report the use of gRNA:Cas9 ribonucleoprotein (RNP) complexes engineered extracellular vesicles (EVs) for in vivo gene therapy. By leveraging a novel high-throughput microfluidic droplet-based electroporation system (μDES), we achieved 10-fold enhancement of loading efficiency and more than 1000-fold increase in processing throughput on loading RNP complexes into EVs (RNP-EVs), compared with conventional bulk electroporation. The flow-through droplets serve as enormous bioreactors for offering millisecond pulsed, low-voltage electroporation in a continuous-flow and scalable manner, which minimizes the Joule heating influence and surface alteration to retain natural EV stability and integrity. In the Shaker-1 mouse model of dominant progressive hearing loss, we demonstrated the effective delivery of RNP-EVs into inner ear hair cells, with a clear reduction of Myo7ash1 mRNA expression compared to RNP-loaded lipid-like nanoparticles (RNP-LNPs), leading to significant hearing recovery measured by auditory brainstem responses (ABR).

Enhancing the Cellular Production of Extracellular Vesicles for Developing Therapeutic Applications

Extracellular vesicles (EVs) have various advantageous properties, including a small size, high biocompatibility, efficient cargo loading, and precise cell targeting ability, making them promising tools for therapeutic development. EVs have been increasingly explored for applications like drug delivery. However, due to limited cellular secretion rates of EVs, wide-scale clinical applications are not achievable. Therefore, substantial strategies and research efforts have been devoted to increasing cellular secretion rates of EVs. This review describes various studies exploring different methods to increase the cellular production of EVs, including the application of electrical stimulus, pharmacologic agents, electromagnetic waves, sound waves, shear stress, cell starvation, alcohol, pH, heat, and genetic manipulation. These methods have shown success in increasing EV production, but careful consideration must be given as many of these strategies may alter EV properties and functionalities, and the exact mechanisms causing the increase in cellular production of EVs is generally unknown. Additionally, the methods' effectiveness in increasing EV secretion may diverge with different cell lines and conditions. Further advancements to enhance EV biogenesis secretion for therapeutic development is still a significant need in the field.

Light-induced high-efficient cellular production of immune functional extracellular vesicles

Extracellular vesicle (EV)‐based therapies and vaccines are emerging. However, employment at the scale for population‐based dose development is always a huge bottleneck. In order to overcome such a roadblock, we introduce a simple and straightforward approach for promoting cellular production of dendritic cell derived EVs (DEVs) by leveraging phototherapy based light induction. Under the optimization of light wavelengths, intensities, and exposure times, we achieved more than 13‐fold enhancement in DEV production rate, while maintaining good integral quality and immune function from produced EVs. The LED light at 365 nm is optimal to reliably trigger enhanced cellular production of EVs no matter cell line types. Our observation and other reported studies support longer near UV wavelength does not impair cell growth. We conducted a series of investigations in terms of size, zeta potential, morphology, immune surface markers and cytokines, biocompatibility, cellular uptake behaviour, and immune‐modulation ability on eliciting cellular responses in vitro. We also validated the biodistribution, immunogenicity, and administration safety using light‐promoted DEVs in mice models from both male and female genders. Overall data supports that light promoted DEVs are highly immune functional with great biocompatibility for serving as good therapeutic platforms. The in vivo animal study also demonstrated light‐promoted DEVs are as well tolerated as native DEVs, with no safety concerns. Taken together, the data supports that light promoted DEVs are in excellent quality, high biocompatibility, in vivo tolerant, and viable for serving as an ideal therapeutic platform in scalable production.

Extracellular Vesicles as an Advanced Delivery Biomaterial for Precision Cancer Immunotherapy

In recent years, cancer immunotherapy has been observed in numerous preclinical and clinical studies for showing benefits. However, due to the unpredictable outcomes and low response rates, novel targeting delivery approaches and modulators are needed for being effective to more broader patient populations and cancer types. Compared to synthetic biomaterials, extracellular vesicles (EVs) specifically open a new avenue for improving the efficacy of cancer immunotherapy by offering targeted and site-specific immunity modulation. In this review, the molecular understanding of EV cargos and surface receptors, which underpin cell targeting specificity and precisely modulating immunogenicity, are discussed. Unique properties of EVs are reviewed in terms of their surface markers, intravesicular contents, intrinsic immunity modulatory functions, and pharmacodynamic behavior in vivo with tumor tissue models, highlighting key indications of improved precision cancer immunotherapy. Novel molecular engineered strategies for reprogramming and directing cancer immunotherapeutics, and their unique challenges are also discussed to illuminate EV's future potential as a cancer immunotherapeutic biomaterial.

Pregabalin for hot flashes in women: NCCTG trial N07C1

9513

Background: Hot flashes are a major problem in many women for which better treatment options are needed. Given the known efficacy of gabapentin for decreasing hot flashes, it was decided to evaluate pregabalin, with hopes that it would work better and/or with fewer toxicities. Methods: A three-arm, double-blinded, placebo-controlled randomized trial was developed. Women with bothersome hot flashes (at least 28/week) were randomized to receive either a placebo or target pregabalin oral doses of 75 mg bid or 150 mg bid (starting at 50 mg/d and then increasing the dose at weekly intervals to 50 mg bid, then 75 mg bid, and then, in the higher dose arm, 150 mg bid); patients were treated for 6 weeks. Hot flash numbers and scores (hot flash number times mean severity) were measured using a validated daily hot flash diary. A one-week baseline period preceded initiation of study tablets. The primary endpoint was the average intra-patient difference in hot flash score between baseline and week six, comparing the higher dose pregabalin arm and the placebo arm. With the planned sample size of 55 patients per arm, there was an 80% power and two-sided 5% Type I error rate to detect a difference of 0.54 standard deviations, or 1.08 hot flashes per day, or 2.7 units of hot flash score per day. Results: 207 patients were randomized between 6/20/2008 and 8/21/2008. The study arms were well balanced. Mean/median daily hot flash scores and frequencies for all pts at baseline were 15.7/13.4 and 8.3/7.7, respectively. The table shows the decreases in hot flashes from the baseline to the sixth treatment week. Larger numbers illustrate greater hot flash reductions. Toxicity information, quality of life information, and information regarding the effects of hot flashes on subjective symptoms will be available at the meeting time. Conclusions: Pregabalin reduces hot flashes in women. There appears to be similar effects with both studied doses.

[Table: see text]

No significant financial relationships to disclose.

Aggression in captive pigtail monkey groups: effects of provision of cover

To assess the influence of provision of "cover" on aggressive behavior in captive nonhuman primate groups, concrete cylinders were introduced into rooms in which six groups of pigtail monkeys resided. Basal incidence of aggression was measured prior to introduction of the cylinders and during their presence in the rooms. Four groups, which underwent little or no change in group composition during the study, exhibited substantially less aggression when cover was available than when it was not. Moderate and extreme changes in group composition occurred in two groups; these changes resulted in slight and dramatic increases in aggression, respectively, at the times when the changes occurred. Subjects frequently used the cylinders to avoid the concrete cylinders resulted in decreased aggression in stable groups but did not prevent aggression in groups which underwent moderate or extreme social change.