Mechanisms of polymer degradation and erosion
TL;DR: The most important features of the degradation and erosion of degradable polymers in vitro are discussed in this article, where a brief survey on approaches to polymer degradation and degradation is given.
About: This article is published in Biomaterials.The article was published on 1996-01-01. It has received 1712 citations till now. The article focuses on the topics: Polymer degradation & Polymer.
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TL;DR: It is anticipated that precisely engineered nanoparticles will emerge as the next-generation platform for cancer therapy and many other biomedical applications.
Abstract: In medicine, nanotechnology has sparked a rapidly growing interest as it promises to solve a number of issues associated with conventional therapeutic agents, including their poor water solubility (at least, for most anticancer drugs), lack of targeting capability, nonspecific distribution, systemic toxicity, and low therapeutic index. Over the past several decades, remarkable progress has been made in the development and application of engineered nanoparticles to treat cancer more effectively. For example, therapeutic agents have been integrated with nanoparticles engineered with optimal sizes, shapes, and surface properties to increase their solubility, prolong their circulation half-life, improve their biodistribution, and reduce their immunogenicity. Nanoparticles and their payloads have also been favorably delivered into tumors by taking advantage of the pathophysiological conditions, such as the enhanced permeability and retention effect, and the spatial variations in the pH value. Additionally, targeting ligands (e.g., small organic molecules, peptides, antibodies, and nucleic acids) have been added to the surface of nanoparticles to specifically target cancerous cells through selective binding to the receptors overexpressed on their surface. Furthermore, it has been demonstrated that multiple types of therapeutic drugs and/or diagnostic agents (e.g., contrast agents) could be delivered through the same carrier to enable combination therapy with a potential to overcome multidrug resistance, and real-time readout on the treatment efficacy. It is anticipated that precisely engineered nanoparticles will emerge as the next-generation platform for cancer therapy and many other biomedical applications.
1,603 citations
TL;DR: Magnesium and its alloys have been investigated recently by many authors as a suitable biodegradable biomaterial as mentioned in this paper, and the latest achievements and comment on the selection and use, test methods and the approaches to develop and produce magnesium alloys that are intended to perform clinically with an appropriate host response.
Abstract: Biodegradable metals are breaking the current paradigm in biomaterial science to develop only corrosion resistant metals. In particular, metals which consist of trace elements existing in the human body are promising candidates for temporary implant materials. These implants would be temporarily needed to provide mechanical support during the healing process of the injured or pathological tissue. Magnesium and its alloys have been investigated recently by many authors as a suitable biodegradable biomaterial. In this investigative review we would like to summarize the latest achievements and comment on the selection and use, test methods and the approaches to develop and produce magnesium alloys that are intended to perform clinically with an appropriate host response.
1,569 citations
TL;DR: In this review, the evolution of different metals, ceramics and polymers most commonly used in orthopaedic applications is discussed, as well as the different approaches used to fulfil the challenges faced by this medical field.
Abstract: At present, strong requirements in orthopaedics are still to be met, both in bone and joint substitution and in the repair and regeneration of bone defects. In this framework, tremendous advances in the biomaterials field have been made in the last 50 years where materials intended for biomedical purposes have evolved through three different generations, namely first generation (bioinert materials), second generation (bioactive and biodegradable materials) and third generation (materials designed to stimulate specific responses at the molecular level). In this review, the evolution of different metals, ceramics and polymers most commonly used in orthopaedic applications is discussed, as well as the different approaches used to fulfil the challenges faced by this medical field.
1,220 citations
Cites background from "Mechanisms of polymer degradation a..."
...In an aqueous environment, water penetrates the bulk of the polymer sample and attacks preferentially the chemical bonds of the amorphous phase, shortening the polymer chains (Gopferich 1996)....
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TL;DR: Dental polymer networks have been shown to be susceptible to hygroscopic and hydrolytic effects to varying extents dependent upon their chemistry and structure, and these effects on the clinical performance of polymer restoratives is largely unknown.
1,190 citations
Cites background from "Mechanisms of polymer degradation a..."
...In any case, this manuscript will only be concerned with non-degradable polymers, defined as those requiring a much longer time to degrade than their expected time of service [1]....
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...Reviews of polymer degradation mechanisms have been published [1,24]....
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TL;DR: An overview on the current state of the art of mathematical modeling of drug delivery, including empirical/semi-empirical and mechanistic realistic models is given, Analytical as well as numerical solutions are described and various practical examples are given.
1,094 citations
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TL;DR: Monodisperse biodegradable nanospheres were developed from amphiphilic copolymers composed of two biocompatible blocks and exhibited dramatically increased blood circulation times and reduced liver accumulation in mice.
Abstract: Injectable nanoparticulate carriers have important potential applications such as site-specific drug delivery or medical imaging. Conventional carriers, however, cannot generally be used because they are eliminated by the reticulo-endothelial system within seconds or minutes after intravenous injection. To address these limitations, monodisperse biodegradable nanospheres were developed from amphiphilic copolymers composed of two biocompatible blocks. The nanospheres exhibited dramatically increased blood circulation times and reduced liver accumulation in mice. Furthermore, they entrapped up to 45 percent by weight of the drug in the dense core in a one-step procedure and could be freeze-dried and easily redispersed without additives in aqueous solutions.
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TL;DR: Conventional forms of drug administration generally rely on pills, eye drops, ointments, and intravenous solutions, but a number of novel drug delivery approaches have been developed, which may revolutionize the way many drugs are delivered.
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