Improved Speech Intelligibility in Subjects With Stable Sensorineural Hearing Loss Following Intratympanic Dosing of FX-322 in a Phase 1b Study.

OBJECTIVES: There are no approved pharmacologic therapies for chronic sensorineural hearing loss (SNHL). The combination of CHIR99021+valproic acid (CV, FX-322) has been shown to regenerate mammalian cochlear hair cells ex vivo. The objectives were to characterize the cochlear pharmacokinetic profile of CV in guinea pigs, then measure FX-322 in human perilymph samples, and finally assess safety and audiometric effects of FX-322 in humans with chronic SNHL. STUDY DESIGNS: Middle ear residence, cochlear distribution, and elimination profiles of FX-322 were assessed in guinea pigs. Human perilymph sampling following intratympanic FX-322 dosing was performed in an open-label study in cochlear implant subjects. Unilateral intratympanic FX-322 was assessed in a Phase 1b prospective, randomized, double-blinded, placebo-controlled clinical trial. SETTING: Three private otolaryngology practices in the US. PATIENTS: Individuals diagnosed with mild to moderately severe chronic SNHL (≤70 dB standard pure-tone average) in one or both ears that was stable for ≥6 months, medical histories consistent with noise-induced or idiopathic sudden SNHL, and no significant vestibular symptoms. INTERVENTIONS: Intratympanic FX-322. MAIN OUTCOME MEASURES: Pharmacokinetics of FX-322 in perilymph and safety and audiometric effects. RESULTS: After intratympanic delivery in guinea pigs and humans, FX-322 levels in the cochlear extended high-frequency region were observed and projected to be pharmacologically active in humans. A single dose of FX-322 in SNHL subjects was well tolerated with mild, transient treatment-related adverse events (n = 15 FX-322 vs 8 placebo). Of the six patients treated with FX-322 who had baseline word recognition in quiet scores below 90%, four showed clinically meaningful improvements (absolute word recognition improved 18-42%, exceeding the 95% confidence interval determined by previously published criteria). No significant changes in placebo-injected ears were observed. At the group level, FX-322 subjects outperformed placebo group in word recognition in quiet when averaged across all time points, with a mean improvement from baseline of 18.9% (p = 0.029). For words in noise, the treated group showed a mean 1.3 dB signal-to-noise ratio improvement (p = 0.012) relative to their baseline scores while placebo-treated subjects did not (-0.21 dB, p = 0.71). CONCLUSIONS: Delivery of FX-322 to the extended high-frequency region of the cochlea is well tolerated and enhances speech recognition performance in multiple subjects with stable chronic hearing loss.

Approaches to Treat Sensorineural Hearing Loss by Hair-Cell Regeneration: The Current State of Therapeutic Developments and Their Potential Impact on Audiological Clinical Practice.

Sensorineural hearing loss (SNHL) is typically a permanent and often progressive condition that is commonly attributed to sensory cell loss. All vertebrates except mammals can regenerate lost sensory cells. Thus, SNHL is currently only treated with hearing aids or cochlear implants. There has been extensive research to understand how regeneration occurs in nonmammals, how hair cells form during development, and what limits regeneration in maturing mammals. These studies motivated efforts to identify therapeutic interventions to regenerate hair cells as a treatment for hearing loss, with a focus on targeting supporting cells to form new sensory hair cells. The approaches include gene therapy and small molecule delivery to the inner ear. At the time of this publication, early-stage clinical trials have been conducted to test targets that have shown evidence of regenerating sensory hair cells in preclinical models. As these potential treatments move closer to a clinical reality, it will be important to understand which therapeutic option is most appropriate for a given population. It is also important to consider which audiological tests should be administered to identify hearing improvement while considering the pharmacokinetics and mechanism of a given approach. Some impacts on audiological practice could include implementing less common audiological measures as standard procedure. As devices are not capable of repairing the damaged underlying biology, hair-cell regeneration treatments could allow patients to benefit more from their devices, move from a cochlear implant candidate to a hearing aid candidate, or move a subject to not needing an assistive device. Here, we describe the background, current state, and future implications of hair-cell regeneration research.

The Yale Center for Biomedical Innovation and Technology (CBIT): One Model to Accelerate Impact From Academic Health Care Innovation.

The process of translating academic biomedical advances into clinical care improvements is difficult, risky, expensive, and poorly understood. Notably, many clinicians who identify health care problems do not have the time or expertise to solve the problems, and many academic researchers are unaware of important gaps in clinical care to which their expertise may apply.Recognizing an opportunity to connect people who can identify health care problems with those who can solve them, the Yale Center for Biomedical Innovation and Technology (CBIT) was established in 2014 to educate and enhance the impact of health care innovators. The authors review other health care innovation centers and describe best practices borrowed by Yale CBIT, which tailored its activities and approach to its unique ecosystem.In four years, Yale CBIT has affected over 3,000 people and established a health care innovation cycle as an efficient strategy to guide translational research. Yale CBIT has created or supported graduate and undergraduate courses, clinical immersion programs for industry partners, and large health care hackathon events. Over 200 projects have been submitted to CBIT for mentorship, and some of those projects have been commercialized and raised millions of dollars of follow-on funding.The authors present Yale CBIT as one model of accelerating the impact of academic medicine on clinical practice and outcomes. The project advising strategy is intended to be a template to maximize the efficiency of biomedical innovation and ultimately improve the outcomes and experiences of future patients.

Anti-infection trauma devices with drug release and nonfouling surface modification.

OBJECTIVES: By coupling an antimicrobial release with a highly nonfouling betaine modification on titanium, this approach innovatively addresses the initial bacterial challenge and the longer term biofilm formation on trauma devices. METHODS: Titanium substrates were modified to obtain a polymer reservoir for chlorhexidine (CHX) and a polybetaine surface layer. The surface was characterized by infrared spectroscopy, scanning electron microscopy, laser confocal scanning microscopy, and a radiolabeled fibrinogen assay. The in vitro drug release profiles were measured using an ultraviolet-visible spectroscopy and a high-performance liquid chromatography. The efficacy to inhibit surface biofilm formation was determined by a bacterial adherence assay. The surface modification's bonding strength to the titanium substrate was measured, and its resistance to abrasion was tested ex vivo. Additionally, the biocompatibility was tested after ISO 10993 procedures. RESULTS: Titanium surfaces were successfully modified with a conformal and strongly bound polymer layer. No scratches were observed when inserting the modified titanium wires into porcine femur, and preservation of modification was confirmed by infrared spectroscopy. Controlled release of CHX was demonstrated for more than 8 weeks, and different formulations were tailored for different release rates. Greater than 3 log (99.9%) reductions in bacterial adherence were achieved after serum exposure. Additionally, the nonfouling properties were retained after several weeks of CHX release. Modified materials passed ISO 10993 testing for permanent implant devices. CONCLUSIONS: By innovatively addressing the initial bacterial challenge and longer term biofilm formation on trauma devices, this approach may be a superior solution to the current biofilm control technology.

Polybetaine modification of PDMS microfluidic devices to resist thrombus formation in whole blood.

Assembled polydimethylsiloxane microfluidic devices were modified with a sulfobetaine polymer through continuous "tip-to-tip" modification, significantly reducing blood clotting and extending device patency under blood flow. This technology can be designed to enable the development of devices that can continuously work in whole blood, especially in an extracorporeal or in vivo environment.

Rapid, nondestructive estimation of surface polymer layer thickness using attenuated total reflection fourier transform infrared (ATR FT-IR) spectroscopy and synthetic spectra derived from optical principles.

We have developed a rapid, nondestructive analytical method that estimates the thickness of a surface polymer layer with high precision but unknown accuracy using a single attenuated total reflection Fourier transform infrared (ATR FT-IR) measurement. Because the method is rapid, nondestructive, and requires no sample preparation, it is ideal as a process analytical technique. Prior to implementation, the ATR FT-IR spectrum of the substrate layer pure component and the ATR FT-IR and real refractive index spectra of the surface layer pure component must be known. From these three input spectra a synthetic mid-infrared spectral matrix of surface layers 0 nm to 10,000 nm thick on substrate is created de novo. A minimum statistical distance match between a process sample's ATR FT-IR spectrum and the synthetic spectral matrix provides the thickness of that sample. We show that this method can be used to successfully estimate the thickness of polysulfobetaine surface modification, a hydrated polymeric surface layer covalently bonded onto a polyetherurethane substrate. A database of 1850 sample spectra was examined. Spectrochemical matrix-effect unknowns, such as the nonuniform and molecularly novel polysulfobetaine-polyetherurethane interface, were found to be minimal. A partial least squares regression analysis of the database spectra versus their thicknesses as calculated by the method described yielded an estimate of precision of ±52 nm.

Vascular catheters with a nonleaching poly-sulfobetaine surface modification reduce thrombus formation and microbial attachment.

Adherence of proteins, cells, and microorganisms to the surface of venous catheters contributes to catheter occlusion, venous thrombosis, thrombotic embolism, and infections. These complications lengthen hospital stays and increase patient morbidity and mortality. Current technologies for inhibiting these complications are limited in duration of efficacy and may induce adverse side effects. To prevent complications over the life span of a device without using active drugs, we modified a catheter with the nonleaching polymeric sulfobetaine (polySB), which coordinates water molecules to the catheter surface. The modified surface effectively reduced protein, mammalian cell, and microbial attachment in vitro and in vivo. Relative to commercial catheters, polySB-modified catheters exposed to human blood in vitro had a >98% reduction in the attachment and a significant reduction in activation of platelets, lymphocytes, monocytes, and neutrophils. Additionally, the accumulation of thrombotic material on the catheter surface was reduced by >99% even after catheters were exposed to serum in vitro for 60 days. In vivo, in a highly thrombogenic canine model, device- and vessel-associated thrombus was reduced by 99%. In vitro adherence of a broad spectrum of microorganisms was reduced on both the external and the internal surfaces of polySB-modified catheters compared to unmodified catheters. When unmodified and polySB-modified catheters were exposed to the same bacterial challenge and implanted into animals, 50% less inflammation and fewer bacteria were associated with polySB-modified catheters. This nonleaching, polySB-modified catheter could have a major impact on reducing thrombosis and infection, thus improving patient health.

Controlling the release of peptide antimicrobial agents from surfaces.

Medical conditions are often exacerbated by the onset of infection caused by hospital dwelling bacteria such as Staphylococcus aureus. Antibiotics taken orally or intravenously can require large and frequent doses, further contributing to the sharp rise in resistant bacteria observed over the past several decades. These existing antibiotics are also often ineffective in preventing biofilm formation, a common cause of medical device failure. Local delivery of new therapeutic agents that do not allow bacterial resistance to occur, such as antimicrobial peptides, could alleviate many of the problems associated with current antibacterial treatments. By taking advantage of the versatility of layer-by-layer assembly of polymer thin films, ponericin G1, an antimicrobial peptide known to be highly active against S. aureus, was incorporated into a hydrolytically degradable polyelectrolyte multilayer film. Several film architectures were examined to obtain various drug loadings that ranged from 20 to 150 microg/cm2. Release was observed over approximately ten days, with varying release profiles, including burst as well as linear release. Results indicated that film-released peptide did not suffer any loss in activity against S. aureus and was able to inhibit bacteria attachment, a necessary step in preventing biofilm formation. Additionally, all films were found to be biocompatible with the relevant wound healing cells, NIH 3T3 fibroblasts and human umbilical vein endothelial cells. These films provide the level of control over drug loading and release kinetics required in medically relevant applications including coatings for implant materials and bandages, while eliminating susceptibility to bacterial resistance.

Optimization of protein fusion partner length for maximizing in vitro translation of peptides.

Using protein fusion partners for in vitro translation may increase solubility, assist in purification, or allow detection of small proteins and peptides. Here we show that the molar yield of peptide in a batch reaction may be maximized by optimizing the length of the translated product, which is composed of the fusion partner plus the peptide. Using truncated versions of GFP as a series of fusion partners, the molar yield increased approximately 3-fold as the length of the translated product was reduced from 250 to 100 amino acids. When the translated product was shortened below roughly 100 amino acids, molar yield fell as a result of proteolysis. This trend was verified using two fusion partners with different amino acid sequences. Furthermore, protease inhibitors were used to confirm that proteases were responsible for limiting accumulation of peptides below the optimal length.

A linguistic model for the rational design of antimicrobial peptides.

Antimicrobial peptides (AmPs) are small proteins that are used by the innate immune system to combat bacterial infection in multicellular eukaryotes. There is mounting evidence that these peptides are less susceptible to bacterial resistance than traditional antibiotics and could form the basis for a new class of therapeutic agents. Here we report the rational design of new AmPs that show limited homology to naturally occurring proteins but have strong bacteriostatic activity against several species of bacteria, including Staphylococcus aureus and Bacillus anthracis. These peptides were designed using a linguistic model of natural AmPs: we treated the amino-acid sequences of natural AmPs as a formal language and built a set of regular grammars to describe this language. We used this set of grammars to create new, unnatural AmP sequences. Our peptides conform to the formal syntax of natural antimicrobial peptides but populate a previously unexplored region of protein sequence space.