http://drugdelivery.chbe.gatech.edu/Papers/2004/Prausnitz%20ADDR%202004.pdf

Microneedles for transdermal drug delivery.

Microneedles for drug and vaccine delivery.

Biodegradable polymer microneedles: fabrication, mechanics and transdermal drug delivery

Dissolving microneedles for transdermal drug delivery.

Transdermal drug delivery offers a number of advantages for the patient, due not only its non-invasive and convenient nature, but also factors such as avoidance of first pass metabolism and prevention of gastrointestinal degradation. It has been demonstrated that microneedle arrays can increase the number of compounds amenable to transdermal delivery by penetrating the skin's protective barrier, the stratum corneum , and creating a pathway for drug permeation to the dermal tissue below. Microneedles have been extensively investigated in recent decades for drug and vaccine delivery as well as minimally invasive patient monitoring/diagnosis. This review focuses on a range of critically important aspects of microneedle technology, namely their material composition, manufacturing techniques, methods of evaluation and commercial translation to the clinic for patient benefit and economic return. Microneedle research and development is finally now at the stage where commercialisation is a realistic possibility. However, progress is still required in the areas of scaled-up manufacture and regulatory approval.

/pdf/microneedle-arrays-as-transdermal-and-intradermal-drug-2noob5nntj.pdf

Microneedle arrays as transdermal and intradermal drug delivery systems: Materials science, manufacture and commercial development

http://drugdelivery.chbe.gatech.edu/Papers/2004/Davis%20J%20Biomech%202004.pdf

Insertion of microneedles into skin: measurement and prediction of insertion force and needle fracture force.

Abstract There is a growing interest in the use of virtual representations of the knee for musculoskeletal research and clinical decision making, and to generate digital evidence for design and regulation of implants. Accessibility to previously developed models and related digital assets can dramatically reduce barriers to entry to conduct simulation-based studies of the knee joint and therefore help accelerate scientific discovery and clinical innovations. Development of models for finite element analysis is a demanding process that is both time consuming and resource intensive. It necessitates expertise to transform raw data to reliable virtual representations. Modeling and simulation workflow has many processes such as image segmentation, surface geometry generation, mesh generation and finally, creation of a finite element representation with relevant loading and boundary conditions. The outcome of the workflow is not only the end-point knee model but also many other digital by-products. When all of these data, derivate assets, and tools are freely and openly accessible, researchers can bypass some or all the steps required to build models and focus on using them to address their research goals. With provenance to specimen-specific anatomical and mechanical data and traceability of digital assets throughout the whole lifecycle of the model, reproducibility and credibility of the modeling practice can be established. The objective of this study is to disseminate Open Knee(s), a cohort of eight knee models (and relevant digital assets) for finite element analysis, that are based on comprehensive specimen-specific imaging data. In addition, the models and by-products of modeling workflows are described along with model development strategies and tools. Passive flexion served as a test simulation case, demonstrating an end-user application. Potential roadmaps for reuse of Open Knee(s) are also discussed. 

/pdf/open-knee-s-a-free-and-open-source-library-of-specimen-1br3rxt7.pdf

Open Knee(s): A Free and Open Source Library of Specimen-Specific Models and Related Digital Assets for Finite Element Analysis of the Knee Joint

Capturing the surface mechanics of musculoskeletal extremities would enhance the realism of life-like mechanics imposed on the limbs within surgical simulations haptics. Other fields that rely on surface manipulation, such as garment or prosthetic design, would also benefit from characterization of tissue surface mechanics. Eight homogeneous tissue models were developed for the upper and lower legs and arms of two donors. Ultrasound indentation data was used to drive an inverse finite element analysis for individualized determination of region-specific material coefficients for the lumped tissue. A novel calibration strategy was implemented by using a ratio based adjustment of tissue properties from linear regression of model predicted and experimental responses. This strategy reduced requirement of simulations to an average of under four iterations. These free and open-source specimen-specific models can serve as templates for simulations focused on mechanical manipulations of limb surfaces.

Benjamin J Landis

Papers

Insertion of microneedles into skin: measurement and prediction of insertion force and needle fracture force.

Open Knee(s): A Free and Open Source Library of Specimen-Specific Models and Related Digital Assets for Finite Element Analysis of the Knee Joint

Template models for simulation of surface manipulation of musculoskeletal extremities