Axon mimicking hydrophilic hollow polycaprolactone microfibres for diffusion magnetic resonance imaging.

Highly hydrophilic hollow polycaprolactone (PCL) microfibres were developed as building elements to create tissue-mimicking test objects (phantoms) for validation of diffusion magnetic resonance imaging (MRI). These microfibres were fabricated by the co-electrospinning of PCL-polysiloxane-based surfactant (PSi) mixture as shell and polyethylene oxide as core. The addition of PSi had a significant effect on the size of resultant electrospun fibres and the formation of hollow microfibres. The presence of PSi in both co-electrospun PCL microfibre surface and cross-section, revealed by X-ray energy dispersive spectroscopy (EDX), enabled water to wet these fibres completely (i.e., zero contact angle) and remained active for up to 12 months after immersing in water. PCL and PCL-PSi fibres with uniaxial orientation were constructed into water-filled phantoms. MR measurement revealed that water molecules diffuse anisotropically in the PCL-PSi phantom. Co-electrospun hollow PCL-PSi microfibres have desirable hydrophilic properties for the construction of a new generation of tissue-mimicking dMRI phantoms.

Hollow Polycaprolactone Microspheres with/without a Single Surface Hole by Co-Electrospraying.

We describe the co-electrospraying of hollow microspheres from a polycaprolactone (PCL) shell solution and various core solutions including water, cyclohexane, poly(ethylene oxide) (PEO), and polyethylene glycol (PEG), using different collectors. The morphologies of the resultant microspheres were characterized by scanning electron microscopy (SEM), confocal microscopy, and nano-X-ray computed tomography (nano-XCT). The core/shell solution miscibility played an important role in the co-electrospraying process and the formation of microsphere structures. Spherical particles were more likely to be produced from miscible combinations of core/shell solutions than from immiscible ones. Hollow PCL microspheres with a single hole in their surfaces were produced when an ethanol bath was used as the collector. The mechanism by which the core/shell structure is transformed into single-hole hollow microspheres is proposed to be primarily based on the evaporation through the shell and extraction by ethanol of the core solution and is described in detail. Additionally, we present a 3D macroscopic tubular structure composed of hollow PCL microspheres, directly assembled on a copper wire collector during co-electrospraying. SEM and nano-XCT confirm that microspheres in the 3D bulk structure remain hollow.

A modular self-assembly approach to functionalised ß-sheet peptide hydrogel biomaterials.

Two complementary ß-sheet-forming decapeptides have been created that form binary self-repairing hydrogels upon combination of the respective free-flowing peptide solutions at pH 7 and >0.28 wt%. The component peptides showed little structure separately but formed extended ß-sheet fibres upon mixing, which became entangled to produce stiff hydrogels. Microscopy revealed two major structures; thin fibrils with a twisted or helical appearance and with widths comparable to the predicted lengths of the peptides within a ß-sheet, and thicker, longer, interwoven fibres that appear to comprise laterally-packed fibrils. A range of gel stiffnesses (G' from 0.05 to 100 kPa) could be attained in this system by altering the assembly conditions, stiffnesses that cover the rheological properties desirable for cell culture scaffolds. Doping in a RGD-tagged component peptide at 5 mol% improved 3T3 fibroblast attachment and viability compared to hydrogel fibres without RGD functionalisation.

A versatile approach towards multivalent saccharide displays on magnetic nanoparticles and phospholipid vesicles.

A simple synthetic route has been devised for the production of coating agents that can give multivalent displays of saccharides on the surface of magnetite nanoparticles and phospholipid vesicles. A versatile and potentially high-throughput condensation reaction allowed the rapid synthesis of a variety of glycosylhydrazide conjugates with lipid, resorcinol or catechol termini, each in good yield and high anomeric purity. The hydrolytic stability of these adducts was assessed in D2O at different pD values using (1)H-NMR spectroscopy, whilst quartz crystal microbalance with dissipation monitoring (QCM-D) confirmed that the saccharide functionality on bilayers and on nanoparticles was still available to lectins. These multivalent saccharide displays promoted nanoparticle interactions with cells, for example N-acetylglucosamine-coated nanoparticles interacted much more effectively with 3T3 fibroblasts than uncoated nanoparticles with these cells. Despite potential sensitivity to oxidation, catechol coatings on magnetite nanoparticles were found to be more stable and generate better nanoparticle interactions with fibroblasts than resorcinol coatings.

Release of proteins and enzymes from vesicular compartments by alternating magnetic fields.

The magnetic release of catalytically active enzymes from vesicular compartments within aggregated nanomaterials has been demonstrated. These nanomaterials, magnetic nanoparticle-vesicle aggregates (MNPVs), were formed by the self-assembly of biotinylated silica-coated Fe3O4 nanoparticles, biotinylated vesicles and tetrameric avidin. The unique features of nanoscale magnetite allow adhesion between membranes to be combined with magnetically triggered transit of reagents across membranes. Adding short spacers between the adhesive biotin groups and the nanoparticle or vesicle surfaces was found to strengthen binding to avidin, with binding of avidin to biotinylated bilayers and biotinylated nanoparticles monitored by quartz crystal microgravimetry with dissipation (QCM-D). Three different reagents were released from the vesicle compartments of MNPVs by a pulse of alternating magnetic field, with the release of a dye modelling the release of small molecule substrates, and the release of cytochrome c modelling the release of biological polymers, such as enzymes. To confirm that enzymes could be released and maintain activity, trypsin was encapsulated and shown to digest casein after magnetically triggered release.

Enzymatically triggered peptide hydrogels for 3D cell encapsulation and culture.

We have investigated the possibility of using enzymatically triggered peptide hydrogels for the encapsulation and culture of cells. Based on recent work done on the enzymatically triggered gelation of FEFK (F, phenylalanine; E, glutamic acid; K, lysine) using thermolysin, a protease enzyme from Bacillus Thermoproteolyticus Rokko, we have investigated the possibility of using this gelation triggering mechanism to encapsulate cells within a 3D hydrogel matrix. First, the properties of enzymatically triggered hydrogels prepared in phosphate buffer solution were investigated and compared with the properties of hydrogels prepared in HPLC grade water from our previous work. We showed that the use of phosphate buffer solution allowed the production of hydrogels with very high shear moduli (>1 MPa). The gelation kinetics was also investigated, and the mechanical properties of the system were shown to closely follow the synthesis of the octapeptide by the enzyme through reverse hydrolysis. In a second phase, we developed, on the basis of information acquired, a facile protocol for the encapsulation of cells and plating of the hydrogel. Human dermal fibroblasts were then used to exemplify the use of these materials. FEFEFKFK octapeptide hydrogels prepared under the same conditions and with the same mechanical properties were used as a control. We showed that no significant differences were observed between the two systems and that after a decrease in cell number on day 1, cells start to proliferate. After 5 days of culture, the cells can be seen to start to adopt a stretched morphology typical of fibroblasts. The results clearly show that the protocol developed minimises the potential detrimental effect that thermolysin can have on the cells and that these enzymatically triggered hydrogels can be used for the 3D encapsulation and culture of cells.

Enhanced remineralisation ability and antibacterial properties of sol-gel glass ionomer cement modified by fluoride containing strontium-based bioactive glass or strontium-containing fluorapatite.

OBJECTIVES: This study aimed to compare two types of bioactive additives which were strontium-containing fluorinated bioactive glass (SrBGF) or strontium-containing fluorapatite (SrFA) added to sol-gel derived glass ionomer cement (SGIC). The objective was to develop antibacterial and mineralisation properties, using bioactive additives, to minimize the occurrence of caries lesions in caries disease. METHODS: Synthesized SrBGF and SrFA nanoparticles were added to SGIC at 1 wt% concentration to improve antibacterial properties against S. mutans, promote remineralisation, and hASCs and hDPSCs viability. Surface roughness and ion-releasing behavior were also evaluated to clarify the effect on the materials. Antibacterial activity was measured via agar disc diffusion and bacterial adhesion. Remineralisation ability was assessed by applying the material to demineralised teeth and subjecting them to a 14-day pH cycle, followed by microCT and SEM-EDS analysis. RESULTS: The addition of SrFA into SGIC significantly improved its antibacterial property. SGIC modified with either SrBGF or SrFA additives could similarly induce apatite crystal precipitation onto demineralised dentin and increase dentin density, indicating its ability to remineralise dentin. Moreover, this study also showed that SGIC modified with SrBGF or SrFA additives had promising results on the in vitro cytotoxicity of hASC and hDPSC. SIGNIFICANT: SrFA has superior antibacterial property as compared to SrBGF while demonstrating equal remineralisation ability. Furthermore, the modified SGIC showed promising results in reducing the cytotoxicity of hASCs and hDPSCs, indicating its potential for managing caries.

Primary human osteoblast and mesenchymal stem cell responses to apatite/tricalcium phosphate bone cement modified with polyacrylic acid and bioactive glass.

In this work, three different modified cements, control apatite/beta-tricalcium phosphate cement (CPC), polymeric CPC (p-CPC), and bioactive glass added polymeric cement (p-CPC/BG) were evaluated regarding their physical properties and the responses of primary human osteoblast cells (HObs) and mesenchymal stem cells (MSCs). Although polyacrylic acid (PAA) increased compressive strength and Young's modulus of the cement, it could cause poor apatite phase formation, a prolonged setting time, and a lower degradation rate. Consequently, bioactive glass (BG) was added to PAA/cement to improve its physical properties, such as compressive strength, Young's modulus, setting time, and degradation. For in vitro testing, HObs viability was assessed under two culture systems with cement-preconditioned medium (indirect) and with cement (direct). HObs viability was examined in direct contact with cements treated by different prewashing conditions. HObs presented a more well spread morphology on cement soaked in medium overnight, as compared to other cements with no treatment and washing in PBS. In addition, the proliferation, differentiation, and total collagen production of both HObs and MSCs adhered to the cement were detected. Cells showed excellent proliferation on PAA/cement and PAA/BG/cement. Furthermore, the higher released Si ion and lower acidosis of PAA/BG/cement-conditioned medium resulted in an increase in osteogenic differentiation (HObs and MSCs) and enhanced collagen production (HObs in osteogenic medium and MSCs in control medium). Therefore, our findings suggest that BG incorporated PAA/apatite/ß-TCP cement could be a promising formula for bone repair applications.

Tissue distribution of angiotensin-converting enzyme 2 (ACE2) receptor in wild animals with a focus on artiodactyls, mustelids and phocids.

Natural cases of zooanthroponotic transmission of SARS-CoV-2 to animals have been reported during the COVID-19 pandemic, including to free-ranging white-tailed deer (Odocoileus virginianus) in North America and farmed American mink (Neovison vison) on multiple continents. To understand the potential for angiotensin-converting enzyme 2 (ACE2)-mediated viral tropism we characterised the distribution of ACE2 receptors in the respiratory and intestinal tissues of a selection of wild and semi-domesticated mammals including artiodactyls (cervids, bovids, camelids, suids and hippopotamus), mustelid and phocid species using immunohistochemistry. Expression of the ACE2 receptor was detected in the bronchial or bronchiolar epithelium of several European and Asiatic deer species, Bactrian camel (Camelus bactrianus), European badger (Meles meles), stoat (Mustela erminea), hippopotamus (Hippopotamus amphibious), harbor seal (Phoca vitulina), and hooded seal (Cystophora cristata). Further receptor mapping in the nasal turbinates and trachea revealed sparse ACE2 receptor expression in the mucosal epithelial cells and occasional occurrence in the submucosal glandular epithelium of Western roe deer (Capreolus capreolus), moose (Alces alces alces), and alpaca (Vicunga pacos). Only the European badger and stoat expressed high levels of ACE2 receptor in the nasal mucosal epithelium, which could suggest high susceptibility to ACE2-mediated respiratory infection. Expression of ACE2 receptor in the intestinal cells was ubiquitous across multiple taxa examined. Our results demonstrate the potential for ACE2-mediated viral infection in a selection of wild mammals and highlight the intra-taxon variability of ACE2 receptor expression, which might influence host susceptibility and infection.

Enzymatic elaboration of oxime-linked glycoconjugates in solution and on liposomes.

Oxime formation is a convenient one-step method for ligating reducing sugars to surfaces, producing a mixture of closed ring α- and ß-anomers along with open-chain (E)- and (Z)-isomers. Here we show that despite existing as a mixture of isomers, N-acetylglucosamine (GlcNAc) oximes can still be substrates for ß(1,4)-galactosyltransferase (ß4GalT1). ß4GalT1 catalysed the galactosylation of GlcNAc oximes by a galactose donor (UDP-Gal) both in solution and in situ on the surface of liposomes, with conversions up to 60% in solution and ca. 15-20% at the liposome surface. It is proposed that the ß-anomer is consumed preferentially but long reaction times allow this isomer to be replenished by equilibration from the remaining isomers. Adding further enzymes gave more complex oligosaccharides, with a combination of α-1,3-fucosyltransferase, ß4GalT1 and the corresponding sugar donors providing Lewis X coated liposomes. However, sialylation using T. cruzi trans-sialidase and sialyllactose provided only very small amounts of sialyl Lewis X (sLex) capped lipid. These observations show that combining oxime formation with enzymatic elaboration will be a useful method for the high-throughput surface modification of drug delivery vehicles, such as liposomes, with cell-targeting oligosaccharides.

Adhesive interactions between cells and biotinylated phospholipid vesicles in alginate: towards new responsive biomaterials.

Creating tissue-mimetic biomaterials able to deliver bioactive compounds after receipt of a remote and non-invasive trigger has so far proved to be challenging. The possible applications of such "smart" biomaterials are vast, ranging from subcutaneous drug delivery to tissue engineering. Self-assembled phospholipid vesicles (liposomes) have the ability to deliver both hydrophilic and hydrophobic drugs, and controlling interactions between functionalized vesicles and cells within biomaterials is an important step for targeted drug delivery to cells. We report an investigation of the interactions between thermally-sensitive and biotin-coated dipalmitoyl phosphatidylcholine vesicles and 3T3 fibroblast cells. The stability of these vesicles under physiological conditions was assessed and their interaction with the cell membranes of fibroblasts in media and alginate/fibronectin mixtures was studied. Stable vesicle-cell aggregates were formed in fluid matrices, and could be a model system for improving the delivery of remotely released drugs within vesicle-containing biomaterials.

Graphene oxide and electroactive reduced graphene oxide-based composite fibrous scaffolds for engineering excitable nerve tissue.

This study systematically investigates the role of graphene oxide (GO) and reduced GO (rGO)/silk-based composite micro/nano-fibrous scaffolds in regulating neuronal cell behavior in vitro, given the limited comparative studies on the effects of graphene family materials on nerve regeneration. Fibrous scaffolds can mimic the architecture of the native extracellular matrix and are potential candidates for tissue engineering peripheral nerves. Silk/GO micro/nano-fibrous scaffolds were electrospun with GO loadings 1 to 10 wt.%, and optionally post-reduced in situ to explore a family of electrically conductive non-woven silk/rGO scaffolds. Conductivities up to 4 × 10-5 S cm-1 were recorded in the dry state, which increased up to 3 × 10-4 S cm-1 after hydration. Neuronoma NG108-15 cells adhered and were viable on all substrates. Enhanced metabolic activity and proliferation were observed on the GO-containing scaffolds, and these cell responses were further promoted for electroactive silk/rGO. Neurite extensions up to 100 µm were achieved by day 5, with maximum outgrowth up to ~250 µm on some of the conductive substrates. These electroactive composite fibrous scaffolds exhibit potential to enhance the neuronal cell response and could be versatile supportive substrates for neural tissue engineering applications.

Coaxial electrospun biomimetic copolymer fibres for application in diffusion magnetic resonance imaging.

Objective. The use of diffusion magnetic resonance imaging (dMRI) opens the door to characterizing brain microstructure because water diffusion is anisotropic in axonal fibres in brain white matter and is sensitive to tissue microstructural changes. As dMRI becomes more sophisticated and microstructurally informative, it has become increasingly important to use a reference object (usually called an imaging phantom) for validation of dMRI. This study aims to develop axon-mimicking physical phantoms from biocopolymers and assess their feasibility for validating dMRI measurements.Approach. We employed a simple and one-step method-coaxial electrospinning-to prepare axon-mimicking hollow microfibres from polycaprolactone-b-polyethylene glycol (PCL-b-PEG) and poly(D, L-lactide-co-glycolic) acid (PLGA), and used them as building elements to create axon-mimicking phantoms. Electrospinning was firstly conducted using two types of PCL-b-PEG and two types of PLGA with different molecular weights in various solvents, with different polymer concentrations, for determining their spinnability. Polymer/solvent concentration combinations with good fibre spinnability were used as the shell material in the following co-electrospinning process in which the polyethylene oxide polymer was used as the core material. Following the microstructural characterization of both electrospun and co-electrospun fibres using optical and electron microscopy, two prototype phantoms were constructed from co-electrospun anisotropic hollow microfibres after inserting them into water-filled test tubes.Main results. Hollow microfibres that mimic the axon microstructure were successfully prepared from the appropriate core and shell material combinations. dMRI measurements of two phantoms on a 7 tesla (T) pre-clinical scanner revealed that diffusivity and anisotropy measurements are in the range of brain white matter.Significance. This feasibility study showed that co-electrospun PCL-b-PEG and PLGA microfibre-based axon-mimicking phantoms could be used in the validation of dMRI methods which seek to characterize white matter microstructure.

Directing the morphology and differentiation of skeletal muscle cells using oriented cellulose nanowhiskers.

Radially oriented submonolayer surfaces of 10-15 nm diameter cellulose nanowhiskers (CNWs) were prepared by spin-coating. The response of myoblasts (muscle cells) to the surfaces was assessed using atomic force microscopy (AFM), immunocytochemistry, and image analysis. Despite the small size of the CNWs, the myoblasts oriented along the CNW surfaces. Upon differentiation, the myoblasts produced striking radial patterns of myotubes, following the radial pattern of the CNWs. This facile method of nanopatterning surfaces may be applied where the directed growth of tissue is required and shows for the first time the potential of CNWs for tissue engineering applications.

Photo-dissociation of self-assembled (anthracene-2-carbonyl)amino acid hydrogels.

Amino acids modified with an N-terminal anthracene group self-assemble into supramolecular hydrogels upon the addition of a range of salts or cell culture medium. Gel-phase photo-dimerisation of gelators results in hydrogel disassembly and was used to recover cells from 3D culture.

Modulation of Neuronal Cell Affinity on PEDOT-PSS Nonwoven Silk Scaffolds for Neural Tissue Engineering.

Peripheral nerve injury is a common consequence of trauma with low regenerative potential. Electroconductive scaffolds can provide appropriate cell growth microenvironments and synergistic cell guidance cues for nerve tissue engineering. In the present study, electrically conductive scaffolds were prepared by conjugating poly (3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT-PSS) or dimethyl sulfoxide (DMSO)-treated PEDOT-PSS on electrospun silk scaffolds. Conductance could be tuned by the coating concentration and was further boosted by DMSO treatment. Analogue NG108-15 neuronal cells were cultured on the scaffolds to evaluate neuronal cell growth, proliferation, and differentiation. Cellular viability was maintained on all scaffold groups while showing comparatively better metabolic activity and proliferation than neat silk. DMSO-treated PEDOT-PSS functionalized scaffolds partially outperformed their PEDOT-PSS counterparts. Differentiation assessments suggested that these PEDOT-PSS assembled silk scaffolds could support neurite sprouting, indicating that they show promise to be used as a future platform to restore electrochemical coupling at the site of injury and preserve normal nerve function.

Co-electrospraying of tumour cell mimicking hollow polymeric microspheres for diffusion magnetic resonance imaging.

Diffusion magnetic resonance imaging (dMRI) is considered as a useful tool to study solid tumours. However, the interpretation of dMRI signal and validation of quantitative measurements of is challenging. One way to address these challenges is by using a standard reference material that can mimic tumour cell microstructure. There is a growing interest in using hollow polymeric microspheres, mainly prepared by multiple steps, as mimics of cells in healthy and diseased tissue. The present work reports on tumour cell-mimicking materials composed of hollow microspheres for application as a standard material in dMRI. These microspheres were prepared via one-step co-electrospraying process. The shell material was poly(d,l-lactic-co-glycolic acid) (PLGA) polymers with different molecule weights and/or ratios of glycolic acid-to-lactic, while the core was polyethylene glycol (PEG) or ethylene glycol. The resultant co-electrosprayed products were characterised by optical microscopy, scanning electron microscopy (SEM) and synchrotron X-ray micro-CT. These products were found to have variable structures and morphologies, e.g. from spherical particles with/without surface hole, through beaded fibres to smooth fibres, which mainly depend on PLGA composition and core materials. Only the shell material of PLGA polymer with ester terminated, Mw 50,000-75,000 g mol-1, and lactide:glycolide 85:15 formed hollow microspheres via the co-electrospraying process using the core material of 8 wt% PEG/chloroform as the core. A water-filled test object (or phantom) was designed and constructed from samples of the material generated from co-electrosprayed PLGA microspheres and tested on a 7 T MRI scanner. The preliminary MRI results provide evidence that hollow PLGA microspheres can restrict/hinder water diffusion as cells do in tumour tissue, implying that the phantom may be suitable for use as a quantitative validation and calibration tool for dMRI.

Delivery of human fibroblast cells by piezoelectric drop-on-demand inkjet printing.

A piezoelectric actuated, drop-on-demand inkjet printing system has been used to deliver suspensions of human fibroblast cells from a well-characterized cell line (HT 1080) in order to investigate the behaviour of cells exposed to the mechanical and fluid stresses associated with the printing process. By varying the amplitude and rise time of the electrical pulse used to excite the piezoelectric actuator, it is possible to alter the stresses experienced by the cells. It is shown that the amplitude of the pulse has a small influence on cell survivability with regression analysis showing cell survival rates falling from 98% with a 40 V pulse (indistinguishable from control measurements) to approximately 94% with a 80 V pulse. The rise time of the pulse was found to have no influence on cell survival. Cell viability post-printing was also assessed using the Alamar Blue metabolic assay and the cells that survived were unaffected by the printing process, with neither pulse amplitude nor rise time showing any significant influence on cell viability (using the standard 5% probability threshold). However, inkjet printing requires cell suspensions to be stable over several minutes during the printing process and it was found that after about 20 min printing, some cell agglomeration or sedimentation affected the printing performance.

Controlling cell morphology on amino acid-modified cellulose.

This study shows that it is possible to affect the morphology and spreading of fibroblast cells on amino acid-modified cellulose-based fibrous networks. Hydrophilic (Gly, Ser), aliphatic (Ala, Val, Leu, Ile) and aromatic amino acids (Phe, Tyr, Trp), coupled to the cellulose via esterification, give rise to different cell morphologies. Modified cellulosic substrates are analysed using time of flight secondary ion mass spectrometry (TOF-SIMS), demonstrating that amino acids are coupled and uniformly distributed over the surface of the samples. Remarkably, it is shown that it is the aromatic amino acids, and in particular Trp, that give rise to significantly enhanced cell spreading. This enhanced effect is shown to be linked to an increase in the adsorption of fibronectin in the presence of aromatic bound amino acids.

Cell viability, proliferation and extracellular matrix production of human annulus fibrosus cells cultured within PDLLA/Bioglass composite foam scaffolds in vitro.

The objective of this study was to assess cell viability, attachment, morphology, proliferation, and collagen and sulphated glycosaminoglycan (s-GAG) production by human annulus fibrosus (HAF) cells cultured in vitro in poly(d,l-lactide) (PDLLA)/Bioglass composite foams. PDLLA foams with different percentages (0, 5 and 30wt.%) of Bioglass particles were prepared by thermally induced phase separation (TIPS) and characterized by scanning electron microscopy (SEM). HAF cell viability in the PDLLA/Bioglass foam was analysed using Live/Dead staining. HAF cell attachment was observed using SEM. An assessment of cell proliferation was conducted using the WST-1 assay. The level of s-GAG and collagen produced by HAF cells was quantified using the 1,9-dimethylmethylene blue (DMMB) assay and Sircoltrade mark assay after 4 weeks of culture. The presence of collagen types I and II within the PDLLA/Bioglass composite foams was analysed using immunohistochemistry. Live/dead staining showed that many viable HAF cells were present on the top surface of the foams as well as penetrating into the internal pore structure, suggesting that the PDLLA/Bioglass composite materials are non-toxic and that the presence of Bioglass particles within PDLLA scaffolds does not inhibit HAF cell growth. The SEM observations revealed that more clusters of HAF cells were attached to the pore walls of both the PDLLA/5BG foam and the PDLLA/30BG foam when compared with the PDLLA/0BG foam. WST-1 assay performed over a period of 4 weeks showed an increased tendency of HAF cells to proliferate within both the PDLLA/5BG foam and the PDLLA/30BG foam when compared with both the tissue culture plastic control and the PDLLA/0BG foam, indicating the presence of Bioglass in the foam has a positive effect on HAF cell proliferation. Sircoltrade mark and DMMB assays showed that HAF cells cultured within the PDLLA/30BG foam had a greater ability to deposit collagen and proteoglycan when compared with the control and the PDLLA/0BG foam after 4 weeks in culture, suggesting that the increase of Bioglass content may induce microenvironmental changes which promote the production of extracellular matrix containing abundant collagen and s-GAG. The immunohistochemical analysis of collagen production demonstrated that collagen produced in all cultures was predominantly of type I. These findings provide preliminary evidence for the use of PDLLA/Bioglass composite as cell-carrier materials for future treatments of the intervertebral disc with damaged AF region.