Recent Developments in Ring Opening Polymerization of Lactones for Biomedical Applications
TL;DR: This review presents the various methods of the synthesis of polyesters and tailoring the properties by proper control of molecular weight, composition, and architecture so as to meet the stringent requirements of devices in the medical field.
About: This article is published in Biomacromolecules.The article was published on 2003-10-23. It has received 1441 citations till now.
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TL;DR: This paper presents the design of highly efficient families of “living” polymerization strategies for the synthesis of block, graft, and star polymers through controlled methods for the controlled synthesis of dendritic macromolecules.
Abstract: Modern synthetic methods have revolutionized polymer chemistry through the development of new and powerful strategies for the controlled synthesis of complex polymer architectures. 1-5 Many of these developments were spawned by new classes of transition metal catalysts for the synthesis of new polyolefin microstructures, 5 the design of highly efficient families of “living” polymerization strategies for the synthesis of block, graft, and star polymers, 6-12 controlled methods for the synthesis of dendritic macromolecules, 3,13,14
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TL;DR: A review of the current status of PLA mass production, processing techniques and current applications is presented, and the methods to tailor PLA properties, the main PLA degradation reactions, PLA products' end-of-life scenarios and the environmental footprint are covered.
800 citations
Cites background from "Recent Developments in Ring Opening..."
...With controlled depolymerization, the cyclic dimer, also referred as lactide, is produced from the lowMw prepolymer PLA [24]....
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TL;DR: In this article, the ring-opening polymerization of cyclic monomers is used as a representative polymerization process to illustrate some of the features of organic catalysts and initiators and compare them to metal-based approaches.
Abstract: Organocatalysis offers a number of opportunities in polymer synthesis and was among the earliest methods of catalyzing the synthesis of polyesters. In the following Perspective we attempt to highlight the opportunities and challenges in the use of organic molecules as catalysts or initiators for polymerization reactions. The ring-opening polymerization of cyclic monomers is used as a representative polymerization process to illustrate some of the features of organic catalysts and initiators and to compare them to metal-based approaches. The convergence of convenience, functional group tolerance, fast rates, and selectivities will continue to drive innovations in polymerization catalysis, and it is our perspective that organocatalysis will continue to play an important role in these developments.
749 citations
TL;DR: This critical review explores how synthetic polymers can be utilised to meet the needs of tissue engineering applications, and how biomimetic principles can be applied to polymeric materials in order to enhance the biological response to scaffolding materials.
Abstract: The field of tissue engineering places complex demands on the materials it uses. The materials chosen to support the intricate processes of tissue development and maintenance need to have properties which serve both the bulk mechanical and structural requirements of the target tissue, as well as enabling interactions with cells at the molecular scale. In this critical review we explore how synthetic polymers can be utilised to meet the needs of tissue engineering applications, and how biomimetic principles can be applied to polymeric materials in order to enhance the biological response to scaffolding materials (105 references).
691 citations
TL;DR: A review of recent developments in the preparation and use of new initiators for the ring opening polymerization of lactide is presented in this article, where the authors compare different classes of initiators including metal complexes, classed according to their group in the periodic table, and carbon-based initiators/organocatalysts.
Abstract: The review summarizes recent developments in the preparation and use of new initiators for the ring opening polymerization of lactide. The review compares different classes of initiator including metal complexes, classed according to their group in the periodic table, and carbon‐based initiators/organocatalysts. Emphasis is placed on the polymerization kinetics and the control exhibited by the different types of initiators. Where useful properties, such as high rates or stereocontrol, have been observed a more detailed examination of the initiator is provided. A further focus of the review is initiators displaying low toxicity and biocompatibility.
638 citations
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TL;DR: This review presents the most outstanding contributions in the field of biodegradable polymeric nanoparticles used as drug delivery systems from 1990 through mid-2000.
3,284 citations
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.
2,827 citations
TL;DR: Kevin Shakesheff investigates new methods of engineering polymer surfaces and the application of these engineered materials in drug delivery and tissue engineering.
Abstract: s, and 360 patents, and edited 12 books. He has also received over 80 major awards including the Gairdner Foundation International Award, Lemelson-MIT prize, ACS’s Applied Polymer Science and Polymer Chemistry Awards, AICHE’s Professional Progress, Bioengineering, Walker and Stine Materials Science and Engineering Awards. In 1989, Dr. Langer was elected to the Institute of Medicine of the National Academy of Sciences, and in 1992 he was elected to both the National Academy of Engineering and the National Academy of Sciences. He is the only active member of all three National Academies. Kevin Shakesheff was born in Ashington, Northumberland, U.K., in 1969. He received his Bacheclor of Pharmacy degree from the University of Nottingham in 1991 and a Ph.D. from the same institution in 1995. In 1996 he became a NATO Postdoctoral Fellow at MIT, Department of Chemical Engineering. He is currently an EPSRC Advanced Fellow at the School of Pharmaceutical Sciences, The University of Nottingham. His research group investigates new methods of engineering polymer surfaces and the application of these engineered materials in drug delivery and tissue engineering. 3182 Chemical Reviews, 1999, Vol. 99, No. 11 Uhrich et al.
2,532 citations
TL;DR: In this paper, the authors focus on properties of biodegradable polymers which make them ideally suited for orthopedic applications where a permanent implant is not desired, and an overview of biocompatibility and approved devices of particular interest in orthopedics are also covered.
2,526 citations
TL;DR: A novel poly(D,L-lactide-co-glycolide) (PLGA) structure with a unique architecture produced by an electrospinning process has been developed for tissue-engineering applications, which acts to support and guide cell growth.
Abstract: The architecture of an engineered tissue substitute plays an important role in modulating tissue growth. A novel poly(D,L-lactide-co-glycolide) (PLGA) structure with a unique architecture produced by an electrospinning process has been developed for tissue-engineering applications. Electrospinning is a process whereby ultra-fine fibers are formed in a high-voltage electrostatic field. The electrospun structure, composed of PLGA fibers ranging from 500 to 800 nm in diameter, features a morphologic similarity to the extracellular matrix (ECM) of natural tissue, which is characterized by a wide range of pore diameter distribution, high porosity, and effective mechanical properties. Such a structure meets the essential design criteria of an ideal engineered scaffold. The favorable cell-matrix interaction within the cellular construct supports the active biocompatibility of the structure. The electrospun nanofibrous structure is capable of supporting cell attachment and proliferation. Cells seeded on this structure tend to maintain phenotypic shape and guided growth according to nanofiber orientation. This novel biodegradable scaffold has potential applications for tissue engineering based upon its unique architecture, which acts to support and guide cell growth.
2,338 citations