When using hydrogel scaffolds for cartilage tissue engineering, two gel properties are particularly important: the equilibrium water content (q, swelling ratio) and compressive modulus, K. In this work, chondrocytes were photoencapsulated in degrading nondegrading poly(ethylene glycol)-based hydrogels to assess extracellular matrix (ECM) formation as a function of these properties. gels, glycosaminoglycan (GAG) was not significantly different gels when q varied from 4.2 9.3 after 2 4 weeks...

This work investigates the cytocompatibility of several photoinitiating systems for potential cell encapsulation applications. Both UV and visible light initiating schemes were examined. The photoinitiators included 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651), 1-hydroxycyclohexyl phenyl ketone 184), 2-methyl-1-[4-(methylthio) phenyl]-2-(4-morpholinyl)-1-propanone 907), 2-hydroxy-1-[4-(hydroxyethoxy)phenyl]-2-methyl-1-propanone (Darocur 2959). camphorquinone (CQ) with ethyl 4-N,...

Abstract In developing a scaffold to support new tissue growth, the degradation rate and mass loss profiles of are important design parameters. this study, hydrogels were prepared by copolymerizing degradable macromer, poly(lactic acid)‐ b ‐poly(ethylene glycol)‐ ‐poly(lactic acid) endcapped with acrylate groups (PEG‐LA‐DA) nondegradable poly(ethylene glycol) dimethacrylate (PEGDM). The resulting exhibited range behavior profiles. Chondrocytes photoencapsulated in gels formulated 50:50,...

Abstract Poly(ethylene glycol) (PEG) hydrogels, modified with RGD, are promising platforms for cell encapsulation and tissue engineering. While these hydrogels offer tunable mechanical properties, the extent of host response may limit their in vivo applicability. The overall objective was to characterize effects hydrogel stiffness on vitro macrophage response. We hypothesized that stiffer substrates induce better attachment, adhesion, increased spreading, which elevates classically activated...

Abstract A major challenge when designing cell scaffolds for chondrocyte delivery in vivo is creating with sufficient mechanical properties to restore initial function while simultaneously controlling temporal changes the gel structure facilitate tissue formation. To address this design challenge, degradable photocrosslinked hydrogels based on poly(ethylene glycol) were investigated. alter gel's properties, fabricated by varying macromer concentration from 10% 15% 20%. twofold increase...

Tuning the degradation profiles of polymer cell carriers to match and tissue growth is an important design parameter for (cartilage) engineering. In this study, degradable hydrogels were fabricated from divinyl, tetrafunctional poly(ethylene glycol) (PEG) multivinyl, multifunctional poly(vinyl alcohol) (PVA) macromers form homopolymer copolymer gels. These gels characterized by their volumetric swelling ratio mass loss as a function time. By variation macromer chemistry functionality, time...

Abstract Chondrocyte deformation, which occurs during mechanical loading, is thought to play an important role in the mechano‐transduction pathway. In designing a scaffold that can be gelled situ for cartilage tissue engineering, consideration influence of loading. This study tested hypothesis changes crosslinking density hydrogel morphology encapsulated chondrocytes response applied load. Chondrocytes were entrapped photo‐crosslinkable scaffolds based on poly(ethylene glycol) (PEG) with two...

To design a carrier for chondrocytes that emulates the critical aspects of native cartilage tissue, hydrogels were formulated from synthetic component based on poly(vinyl alcohol) (PVA) and natural component, negatively charged chondroitin sulfate (ChSA, main proteoglycans). The synthesis photoreactive crosslinkable macromers PVA ChSA is described in detail. A range macroscopic hydrogel properties was obtained by varying macromer molecular weight, concentration, functionality prior to...

Biodegradable poly(2-hydroxyethyl methacrylate)(pHEMA) hydrogels for engineered tissue constructs were developed by the use of atom transfer radical polymerization (ATRP), a degradable cross-linker, and macroinitiator. Hydrogels are appropriate materials engineering scaffolds because their tissue-like mechanical compliance mass properties. However, many that have seen wide application in medicine not biodegradable or cannot be easily cleared from body. pHEMA was selected scaffold material...

Photopolymerizable poly(ethylene glycol) (PEG)- based hydrogels have great potential as in vivo cell delivery vehicles for tissue engineering. However, their success will be dependent on the host response. The objectives this study were to explore response and vitro macrophage commonly used PEG-based hydrogels, PEG containing RGD. Acellular implanted subcutaneously into c57bl/6 mice foreign body (FBR) was compared medical grade silicone. Our findings demonstrated PEG-RGD resulted a FBR...

Application of 3D printed structures via stereolithography (SLA) is limited by imprecise dimensional control and inferior mechanical properties. These challenges attributed to poor understanding polymerization behavior during the printing process inadequate post‐processing methods. The former a modified version Jacob's working curve equation that incorporates resin's sub‐linear response irradiation intensity addressed authors. This new model provides more accurate approach select parameters...

Reducing the foreign body response (FBR) to implanted biomaterials will enhance their performance in tissue engineering. Poly(ethylene glycol) (PEG) hydrogels are increasingly popular for this application due low cost, ease of use, and ability tune compliance via molecular weight cross-linking densities. PEG can elicit chronic inflammation vivo, but recent evidence has suggested that extremely hydrophilic, zwitterionic materials particles evade immune system. To combine advantages PEG-based...

Abstract In engineering a cell‐carrier to support cartilage growth, hydrogels provide unique, largely aqueous environment for 3‐dimensional chondrocyte culture that facilitates nutrient transport yet provides an elastic framework dictating tissue shape and supporting external loads. Although the gel is often >90% water, we demonstrate slight variations in hydrogel chemistry control degradation, evolving macroscopic properties, ultimately secretion distribution of extracellular matrix...