Synthetic biodegradable polymers as orthopedic devices

Middleton, J. C.; Tipton, Arthur James

doi:10.1016/s0142-9612(00)00101-0

Cited by 2,358 publications

(1,898 citation statements)

References 20 publications

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“…We observed that PLGA scaffolds at a ratio of 50 (PLA):50 (PGA) preserved their integrity up to 5 weeks in vitro, which is compatible with the time taken by the cells to synthesize the new ECM [from 9 to 20 days, according to the work performed by Barry and collaborators (Barry et al 2001)] that substitutes the scaffolding material (Middleton and Tipton 2000). Furthermore, PLGA-based constructs allow arthroscopic implantation, making this biomaterial even more attractive for clinical use, since the arthroscopic technique reduces morbidity, surgical time, patient recovery and secondary complications typically derived from open surgery that are routinely performed in tissue engineering strategies for cartilage repair (Villalobos Córdoba et al 2007;Erggelet et al 2007;Niederauer et al 2000).…”

Section: Discussionsupporting

confidence: 72%

Cartilage resurfacing potential of PLGA scaffolds loaded with autologous cells from cartilage, fat, and bone marrow in an ovine model of osteochondral focal defect

et al. 2015

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Current developments in tissue engineering strategies for articular cartilage regeneration focus on the design of supportive three-dimensional scaffolds and their use in combination with cells from different sources. The challenge of translating initial successes in small laboratory animals into the clinics involves pilot studies in large animal models, where safety and efficacy should be investigated during prolonged follow-up periods. Here we present, in a single study, the long-term (up to 1 year) effect of biocompatible porous scaffolds non-seeded and seeded with fresh ex vivo expanded autologous progenitor cells that were derived from three different cell sources [cartilage, fat and bone marrow (BM)] in order to evaluate their advantages as cartilage resurfacing agents. An ovine model of critical size osteochondral focal defect was used and the test items were implanted arthroscopically into the knees. Evidence of regeneration of hyaline quality tissue was observed at 6 and 12 months post-treatment with variable success depending on the cell source. Cartilage and BM-derived mesenchymal stromal cells (MSC), but not those derived from fat, resulted in the best quality of new cartilage, as judged qualitatively by magnetic resonance imaging and macroscopic assessment, and by histological quantitative scores. Given the limitations in sourcing cartilage tissue and the risk of donor site morbidity, BM emerges as a preferential source of MSC for novel cartilage resurfacing therapies of osteochondral defects using copolymeric poly-D,L-lactide-co-glycolide scaffolds.

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Section: Discussionsupporting

confidence: 72%

Cartilage resurfacing potential of PLGA scaffolds loaded with autologous cells from cartilage, fat, and bone marrow in an ovine model of osteochondral focal defect

et al. 2015

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“…PGA, the simplest linear aliphatic polyester is highly crystalline (45-55%), has a high melting point (220 C), and a glass transition temperature of $35 C. PGA alone has a high modulus (7 GPa), and completely degrades in vivo within 4-6 months. 251 Like PLA, PGA has also been used in a bone tissue engineering applications. However, most researchers copolymerize PLA and PGA to increase control over degradation rates and mechanisms for a specific application.…”

Section: Mechanisms Of Polymer Biodegradationmentioning

confidence: 99%

Bone tissue engineering: A review in bone biomimetics and drug delivery strategies

Porter

Ruckh

Popat

2009

Biotechnology Progress

671

499

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Critical‐sized defects in bone, whether induced by primary tumor resection, trauma, or selective surgery have in many cases presented insurmountable challenges to the current gold standard treatment for bone repair. The primary purpose of a tissue‐engineered scaffold is to use engineering principles to incite and promote the natural healing process of bone which does not occur in critical‐sized defects. A synthetic bone scaffold must be biocompatible, biodegradable to allow native tissue integration, and mimic the multidimensional hierarchical structure of native bone. In addition to being physically and chemically biomimetic, an ideal scaffold is capable of eluting bioactive molecules (e.g., BMPs, TGF‐βs, etc., to accelerate extracellular matrix production and tissue integration) or drugs (e.g., antibiotics, cisplatin, etc., to prevent undesired biological response such as sepsis or cancer recurrence) in a temporally and spatially controlled manner. Various biomaterials including ceramics, metals, polymers, and composites have been investigated for their potential as bone scaffold materials. However, due to their tunable physiochemical properties, biocompatibility, and controllable biodegradability, polymers have emerged as the principal material in bone tissue engineering. This article briefly reviews the physiological and anatomical characteristics of native bone, describes key technologies in mimicking the physical and chemical environment of bone using synthetic materials, and provides an overview of local drug delivery as it pertains to bone tissue engineering is included. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009

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“…When the backbone is hydrolytically unstable, these chains will degrade when placed in an aqueous environment. This material property to degrade over time has led to a variety of medical applications [83]. The most commonly used biodegradable materials are polyesters that are derived from so-called poly(a-hydroxy acids), like poly(lactic acid) (polylactide, PLA), and poly(glycolic acid) (polyglycolide, PGA) [27,55,108].…”

Section: Polylactic Acidsmentioning

confidence: 99%

“…Polymers can be produced either by direct condensation of lactic acid, or by ring-opening polymerization of the cyclic lactide dimer ( Fig. 3) [40, 68,83]. Lactic acids in cyclic dimers are bound by two ester bonds; one is broken with a catalyst, which stabilizes the other.…”

Section: Production and Processingmentioning

confidence: 99%