Microneedles for drug and vaccine delivery.

Dissolving microneedles for transdermal drug delivery.

Successful materials design for bone-tissue engineering requires an understanding of the composition and structure of native bone tissue, as well as appropriate selection of biomimetic natural or tunable synthetic materials (biomaterials), such as polymers, bioceramics, metals and composites. Scalable fabrication technologies that enable control over construct architecture at multiple length scales, including three-dimensional printing and electric-field-assisted techniques, can then be employed to process these biomaterials into suitable forms for bone-tissue engineering. In this Review, we provide an overview of materials-design considerations for bone-tissue-engineering applications in both disease modelling and treatment of injuries and disease in humans. We outline the materials-design pathway from implementation strategy through selection of materials and fabrication methods to evaluation. Finally, we discuss unmet needs and current challenges in the development of ideal materials for bone-tissue regeneration and highlight emerging strategies in the field. Design of bone-tissue-engineering materials involves consideration of multiple, often conflicting, requirements. This Review discusses these considerations and highlights scalable technologies that can fabricate natural and synthetic biomaterials (polymers, bioceramics, metals and composites) into forms suitable for bone-tissue-engineering applications in human therapies and disease models.

Materials design for bone-tissue engineering

http://drugdelivery.chbe.gatech.edu/Papers/2007/Gill%20J%20Control%20Release%202007.pdf

Coated microneedles for transdermal delivery

ObjectivesTo design microneedles that minimize pain, this study tested the hypothesis that microneedles cause significantly less pain than a 26-gauge hypodermic needle, and that decreasing microneedle length and the number of microneedles reduces pain in normal human volunteers.MethodsSingle microne

/pdf/effect-of-microneedle-design-on-pain-in-human-volunteers-43yvob4yaz.pdf

Effect of Microneedle Design on Pain in Human Volunteers

Fear of injections may interfere with receipt of vaccines. The frequency, associations, and precipitators of fear-provoking factors of 400 travelers visiting a travel health clinic were evaluated. The median age of this group was 25, 7% were medical staff members, and 2.8% were regular injectors (insulin). Eighty-five (21.7%; 95% confidence interval, 17.3-25.6%) of the travelers indicated that they were afraid of injections, and in 8.2%, the fear was unreasonably intense. Multivariate analysis revealed that watching other people being vaccinated, fear of pain, needle size, and a history of fainting were highly and independently associated with injection phobia. The sensitivity, specificity, and discrimination accuracy of this model were 79.5%, 78.0%, and 78.3%, respectively. Injection phobia and a bad past vaccination experience were significantly associated with fainting. Perceived empathy, on the other hand, was a significant protective factor. Fear of injections was common in this cohort and was highly associated with past fainting after vaccination.

Fear of injections in young adults: prevalence and associations

Background: Helicobacter pylori has been associated with the pathogenesis of antral gastritis, duodenal ulcer, and gastric lymphoma. Eradication of H. pylori has been shown to reverse or prevent relapse of these diseases. Antimicrobials employed in the eradication of H. pylori are not without adverse effects. Newer treatment modalities, therefore, are required. In vitro studies have shown the effectiveness of cinnamon extract against H. pylori and its urease. In this pilot study, we tested the activity of an alcoholic extract of cinnamon in a group of patients infected with H. pylori. 

Materials and methods: Fifteen patients (11 women, 4 men) aged 16 to 79 years were given 40 mg of an alcoholic cinnamon extract twice daily for 4 weeks; eight patients aged 35 to 79 (7 women, 1 man) received placebo. The amount of H. pylori colonization was measured by the 13C urea breath test before and after therapy. 

Results: The mean urea breath test counts in the study and control groups before and after therapy were 22.1 and 23.9 versus 24.4 and 25.9, respectively. The cinnamon extract was well tolerated, and side effects were minimal. 

Conclusions: We concluded that cinnamon extract, at a concentration of 80 mg /day as a single agent, is ineffective in eradicating H. pylori. Combination of cinnamon with other antimicrobials, or cinnamon extract at a higher concentration, however, may prove useful.

Controlled Trial of the Effect of Cinnamon Extract on Helicobacter pylori

Surgical blades are common medical tools. However, blades cannot distinguish between healthy and diseased tissue, thereby creating unnecessary damage, lengthening recovery, and increasing pain. We propose that surgical procedures can rely on natural tissue remodeling tools-enzymes, which are the same tools our body uses to repair itself. Through a combination of nanotechnology and a controllably activated proteolytic enzyme, we performed a targeted surgical task in the oral cavity. More specifically, we engineered nanoparticles that contain collagenase in a deactivated form. Once placed at the surgical site, collagenase was released at a therapeutic concentration and activated by calcium, its biological cofactor that is naturally present in the tissue. Enhanced periodontal remodeling was recorded due to enzymatic cleavage of the supracrestal collagen fibers that connect the teeth to the underlying bone. When positioned in their new orientation, natural tissue repair mechanisms supported soft and hard tissue recovery and reduced tooth relapse. Through the combination of nanotechnology and proteolytic enzymes, localized surgical procedures can now be less invasive.

Yael Nir

Papers

Fear of injections in young adults: prevalence and associations

Controlled Trial of the Effect of Cinnamon Extract on Helicobacter pylori

Proteolytic Nanoparticles Replace a Surgical Blade by Controllably Remodeling the Oral Connective Tissue