Ink-spiring innovations: 3D bioprinting skin models for disease discovery.

Tweetable abstract Inflammatory skin diseases account for most chronic skin conditions. 3D bioprinting is an exciting technology that can revolutionize the understanding and approach to treatment of atopic dermatitis and graft-versus-host disease.

3D bioprinting-a model for skin aging.

Human lifespan continues to extend as an unprecedented number of people reach their seventh and eighth decades of life, unveiling chronic conditions that affect the older adult. Age-related skin conditions include senile purpura, seborrheic keratoses, pemphigus vulgaris, bullous pemphigoid, diabetic foot wounds and skin cancer. Current methods of drug testing prior to clinical trials require the use of pre-clinical animal models, which are often unable to adequately replicate human skin response. Therefore, a reliable model for aged human skin is needed. The current challenges in developing an aged human skin model include the intrinsic variability in skin architecture from person to person. An ideal skin model would incorporate innate functionality such as sensation, vascularization and regeneration. The advent of 3D bioprinting allows us to create human skin equivalent for use as clinical-grade surgical graft, for drug testing and other needs. In this review, we describe the process of human skin aging and outline the steps to create an aged skin model with 3D bioprinting using skin cells (i.e. keratinocytes, fibroblasts and melanocytes). We also provide an overview of current bioprinted skin models, associated limitations and direction for future research.

Design and Validation of an Automated Dilator Prototype for the Treatment of Radiation Induced Vaginal Injury.

Vaginal stenosis (VS) is a common late complication of radiation injury caused by cervical cancer radiotherapy. It is characterized by the narrowing or shortening of the vaginal canal, which is often detrimental to patient quality of life. To address this public health problem, an expandable vaginal dilator was designed for the prevention of VS in cervical cancer survivors. Modeling and benchtop experimentation were used to iteratively characterize the relationship among dilator pressure, expansion, and the load applied to the simulated vaginal wall. Both experimental and simulation results exhibited shared trends relating pressure, dilator expansion, applied load, and resultant displacement of the modeled vaginal walls. Future work will incorporate enhanced Mooney-Rivlin material assumptions and validation of the model with in vivo tests.Clinical Relevance- These results present a design opportunity and treatment paradigm shift to increase patient adherence to VS treatment after cervical cancer radiotherapy. Specifically, gradual expansion of the vaginal dilator increases comfort during the expansion of the vagina, while monitoring the dilator pressure enables the tracking of VS improvement and normalization of vaginal wall compliance.

A comparative study of experimental urinary catheters containing silver and zinc for biofilm inhibition.

Both commercial and experimental antibacterial urinary catheters were investigated for their efficacy in preventing planktonic growth and biofilm formation of Escherichia Coli bacteria in a synthetic urine solution. Experimental antibacterial catheters having thin (<500 µm) dispersions of Ag, Ag/Ag2O, or Zn/Ag2O in polydimethylsiloxane (PDMS) binder all exhibited significant antimicrobial activity, outperforming traditional commercial antibacterial catheters. All experimental catheters prevented planktonic growth of bacteria and did not exhibit biofilm formation during a six-day test period using a colony forming unit (CFU) measurement method. On the other hand, the best performing commercial catheters demonstrated efficacy for only 3 days in planktonic growth tests and formed multiple bacterial colonies in CFU measurements. The Zn/Ag2O/PDMS experimental catheter was the only catheter observed to produce hydrogen peroxide, a reactive oxygen species known to inhibit biofilm formation; lack of detectable hydrogen peroxide production by the Ag2O/PDMS and Ag/Ag2O/PDMS experimental catheters suggests that bactericidal action most likely arises from release of silver ions present in the PDMS coatings.