Natural polymers for the microencapsulation of cells

Abstract

The encapsulation of living mammalian cells within a semi-permeable hydrogel matrix is an attractive procedure for many biomedical and biotechnological applications, such as xenotransplantation, maintenance of stem cell phenotype and bioprinting of three-dimensional scaffolds for tissue engineering and regenerative medicine. In this review, we focus on naturally derived polymers that can form hydrogels under mild conditions and that are thus capable of entrapping cells within controlled volumes. Our emphasis will be on polysaccharides and proteins, including agarose, alginate, carrageenan, chitosan, gellan gum, hyaluronic acid, collagen, elastin, gelatin, fibrin and silk fibroin. We also discuss the technologies commonly employed to encapsulate cells in these hydrogels, with particular attention on microencapsulation.

Design Advances in Particulate Systems for Biomedical Applications

“…[ 45,46 ] Recent advances in the design of biomimetic and biodegradable microcarries with characteristics to be combined with different types of cells open a burgeoning number of possible therapeutic applications. Overviews of microparticulate systems for cell encapsulation have been reported elsewhere [ 44,45 ] including the use of natural-based macromolecules and examples of application in the biomedical fi eld.…”

“…Therefore, the matrix must be permeable to oxygen, to incoming nutrients and to outgoing toxic metabolites. [ 44 ] Alternatives to be explored are based on materials that are able to deliver oxygen to the cells. [ 62,63 ] In specifi c cases, when the entrapped cells are able to secrete molecules of interest (e.g., growth factors), the matrix should be permeable to those bioactive agents.…”

Mikroenkapsüle edilen paratiroid hücrelerinin in-vitro optimizasyonu

“…Bunun en önemli nedeni ultrasafaljinatın, organizmada oluşabilecek olası bir immün yanıttan, oluşturduğu bariyer sayesinde etkilenmemesidir 9 . Tüm bu özellikler birlikte değerlendirildiğinde aljinat tabanlı mikroenkapsülasyon tekniğinin taşıyıcı veya aracı bir sistem gibi özellikle nakil ve benzeri araştırmalarda, kullanılabilirliğini ortaya koymaktadır.…”

Photothermal-modulated drug delivery and magnetic relaxation based on collagen/poly(γ-glutamic acid) hydrogel

“…10,12,13 In contrast, physical hydrogels based on natural polymers exhibit excellent biocompatibility and have been used in humans for many years. 11,12,14,15 However, few resources are available for modulation of the physicochemical properties of natural polymer-based hydrogels adapted to their target applications. 11,14,15 Collagens are one of the major hydrogel component materials studied as drug delivery carriers and scaffolds for cell therapy.…”

“…[1][2][3][4][5][6][7][8][9] By modulating the chemical or physical interactions between natural and/or synthetic polymeric materials, various types of hydrogels have been developed. [10][11][12][13][14][15] Although the chemical gelation strategy using synthetic polymers shows advantages, such as the systematic control of molecular structure and resultant hydrogel properties, toxicity issues still limit their wide adoption in clinical fields. 10,12,13 In contrast, physical hydrogels based on natural polymers exhibit excellent biocompatibility and have been used in humans for many years.…”