https://yunus.hacettepe.edu.tr/~damlacetin/kmu407/index_dosyalar/4.%20makale.pdf

Biodegradable polymers as biomaterials

Biodegradable and bioactive porous polymer/inorganic composite scaffolds for bone tissue engineering

In past two decades poly lactic-co-glycolic acid (PLGA) has been among the most attractive polymeric candidates used to fabricate devices for drug delivery and tissue engineering applications. PLGA is biocompatible and biodegradable, exhibits a wide range of erosion times, has tunable mechanical properties and most importantly, is a FDA approved polymer. In particular, PLGA has been extensively studied for the development of devices for controlled delivery of small molecule drugs, proteins and other macromolecules in commercial use and in research. This manuscript describes the various fabrication techniques for these devices and the factors affecting their degradation and drug release.

/pdf/poly-lactic-co-glycolic-acid-plga-as-biodegradable-1xyztolf10.pdf

Poly Lactic-co-Glycolic Acid (PLGA) as Biodegradable Controlled Drug Delivery Carrier

The return of a forgotten polymer—Polycaprolactone in the 21st century

In the 10 years that have passed since the Nobel prize-winning discovery of RNA interference (RNAi), billions of dollars have been invested in the therapeutic application of gene silencing in humans. Today, there are promising data from ongoing clinical trials for the treatment of age-related macular degeneration and respiratory syncytial virus. Despite these early successes, however, the widespread use of RNAi therapeutics for disease prevention and treatment requires the development of clinically suitable, safe and effective drug delivery vehicles. Here, we provide an update on the progress of RNAi therapeutics and highlight novel synthetic materials for the encapsulation and intracellular delivery of nucleic acids.

Knocking down barriers: advances in siRNA delivery

Mechanisms of polymer degradation and erosion

Why degradable polymers undergo surface erosion or bulk erosion.

Polyethylenimine-based non-viral gene delivery systems.

Mathematical modeling of bioerodible, polymeric drug delivery systems.

Microchips are provided, which control both the rate and time of release of multiple chemical substances and which allow for the release of a wide variety of molecules in either a continuous or pulsatile manner. In all of the preferred embodiments, a material that is impermeable to the drugs or other molecules to be delivered and the surrounding fluids is used as the substrate. Reservoirs are etched into the substrate using either chemical (wet) etching or ion beam (dry) etching techniques well-known in the field of microfabrication. Hundreds to thousands of reservoirs can be fabricated on a single microchip using these techniques. A release system, which includes the molecules to be delivered, is inserted into the reservoirs by injection, inkjet printing or spin coating methods. Exemplary release systems include polymers and polymeric matrices, non-polymeric matrices, and other excipients or diluents. The physical properties of the release system control the rate of release of the molecules. The reservoirs can contain multiple drugs or other molecules in variable dosages. The filled reservoirs can be capped with materials that either degrade, dissolve, or allow the molecules to diffuse passively out of the reservoir over time or materials that, upon application of an electric potential, oxidize to form soluble compounds or ions that dissolve into the surrounding fluids. Release from an active device can be controlled by a preprogrammed microprocessor, remote control, or by biosensors.

Achim Göpferich

Papers

Mechanisms of polymer degradation and erosion

Why degradable polymers undergo surface erosion or bulk erosion.

Polyethylenimine-based non-viral gene delivery systems.

Mathematical modeling of bioerodible, polymeric drug delivery systems.

Microchip drug delivery devices