3D Polycaprolactone Scaffolds Research Articles

Alginate Improves the Chondrogenic Capacity of 3D PCL Scaffolds In Vitro: A Histological Approach.

Polycaprolactone (PCL) scaffolds have demonstrated an effectiveness in articular cartilage regeneration due to their biomechanical properties. On the other hand, alginate hydrogels generate a 3D environment with great chondrogenic potential. Our aim is to generate a mixed PCL/alginate scaffold that combines the chondrogenic properties of the two biomaterials. Porous PCL scaffolds were manufactured using a modified salt-leaching method and embedded in a culture medium or alginate in the presence or absence of chondrocytes. The chondrogenic capacity was studied in vitro. Type II collagen and aggrecan were measured by immunofluorescence, cell morphology by F-actin fluorescence staining and gene expression of COL1A1, COL2A1, ACAN, COL10A1, VEGF, RUNX1 and SOX6 by reverse transcription polymerase chain reaction (RT-PCR). The biocompatibility of the scaffolds was determined in vivo using athymic nude mice and assessed by histopathological and morphometric analysis. Alginate improved the chondrogenic potential of PCL in vitro by increasing the expression of type II collagen and aggrecan, as well as other markers related to chondrogenesis. All scaffolds showed good biocompatibility in the in vivo model. The presence of cells in the scaffolds induced an increase in vascularization of the PCL/alginate scaffolds. The results presented here reinforce the benefits of the combined use of PCL and alginate for the regeneration of articular cartilage.

Combination techniques towards novel drug delivery systems manufacturing: 3D PCL scaffolds enriched with tetracycline-loaded PVP nanoparticles

Drug delivery systems based on synthetic and natural polymers offer a new approach with a capacity to control the release of bio-active agents within time. In this work, we present different designs of Polycaprolactone (PCL) 3D scaffolds containing Polyvinylpyrrolidone (PVP) nanoparticles that can store a hydrophilic drug. The drug delivery system, combined of PCL and PVP polymers fabricated by additive manufacturing, aims for a solution for longer and more stabled drug delivery carrier. The drug, planned to be released to the targeted area, is sprayed with the electrospray method inside PVP nanoparticles on the different layers of the fabricated PCL scaffolds 3D printing. This makes obtaining a layered and porous scaffold and drug-loaded nanoparticles within this structure easier. Obtained PCL scaffolds containing Tetracyclines (Tet) loaded PVP nanoparticles showed that drug encapsulation into the interlayer extended the release time and exhibited a controlled release profile for days. Moreover, produced scaffolds have good biocompatibility and no harmful effects. The combination of 3D scaffolds and drug-loaded nanoparticles aims to develop new functional scaffolds by targeting more efficient and longer-lasting drug delivery.

Polycaprolactone nanofibers colonized by HeLa cells: an alternative for in vitro investigation of fungal infection.

Introduction: In vitro 3D equivalent tissues can be used for studies of fungal infections. Objectives: To develop 3D electrospun nanofibers using polycaprolactone (PCL) colonized by HeLa cells as a possible in vitro model for the investigation of fungal infection. Materials & methods: A PCL solution was synthesized and electrospun. HeLa cells were cultured on the nanostructured PCL scaffolds, forming a 3D structure. Physicochemical, biological and Candida albicans infection assays were performed in this model. Results: The nanostructured PCL scaffolds showed favorable physicochemical characteristics and allowed the colonization of HeLa cells, which showed indications of extracellular matrix production. Conclusions: Fungal infection was evidenced in the 3D nanostructured PCL scaffolds, being viable, economical and compatible to study fungal infections in vitro.

Composite Scaffolds for Bone Tissue Regeneration Based on PCL and Mg-Containing Bioactive Glasses.

Simple SummaryPolycaprolactone (PCL) is a bioresorbable and biocompatible polymer that has been widely used in long-term implants. However, when it comes to regenerative medicine, PCL suffers from some shortcomings such as a slow degradation rate, poor mechanical properties, and low cell adhesion. The incorporation of ceramics such as bioactive glasses into the PCL matrix has yielded a class of hybrid biomaterials with remarkably improved mechanical properties, controllable degradation rates, and enhanced bioactivity, which are suitable for bone tissue engineering. The use of conventional approaches (such as solvent casting and particulate leaching, phase separation, electrospinning, freeze drying, etc.) in realizing these composite scaffolds strongly affects the control of both the internal and the external architecture of scaffolds, including pore size, pore morphology, and overall structure porosity. Accordingly, 3D printing was used in this study because of the benefits offered over conventional methods, such as high flexibility in shape and size, high reproducibility, capabilities of precise control over internal architecture down to the microscale level, and a customized design that can be tailored to specific patient needs. The optimization of the scaffold structure was previously investigated in terms of architecture through the combination of the Taguchi method and CAD drawing, and, in this study, it was investigated by varying the composition of the composite material.Polycaprolactone (PCL) is widely used in additive manufacturing for the construction of scaffolds for tissue engineering because of its good bioresorbability, biocompatibility, and processability. Nevertheless, its use is limited by its inadequate mechanical support, slow degradation rate and the lack of bioactivity and ability to induce cell adhesion and, thus, bone tissue regeneration. In this study, we fabricated 3D PCL scaffolds reinforced with a novel Mg-doped bioactive glass (Mg-BG) characterized by good mechanical properties and biological reactivity. An optimization of the printing parameters and scaffold fabrication was performed; furthermore, an extensive microtopography characterization by scanning electron microscopy and atomic force microscopy was carried out. Nano-indentation tests accounted for the mechanical properties of the scaffolds, whereas SBF tests and cytotoxicity tests using human bone-marrow-derived mesenchymal stem cells (BM-MSCs) were performed to evaluate the bioactivity and in vitro viability. Our results showed that a 50/50 wt% of the polymer-to-glass ratio provides scaffolds with a dense and homogeneous distribution of Mg-BG particles at the surface and roughness twice that of pure PCL scaffolds. Compared to pure PCL (hardness H = 35 ± 2 MPa and Young’s elastic modulus E = 0.80 ± 0.05 GPa), the 50/50 wt% formulation showed H = 52 ± 11 MPa and E = 2.0 ± 0.2 GPa, hence, it was close to those of trabecular bone. The high level of biocompatibility, bioactivity, and cell adhesion encourages the use of the composite PCL/Mg-BG scaffolds in promoting cell viability and supporting mechanical loading in the host trabecular bone.

Surface modification of a three-dimensional polycaprolactone scaffold by polydopamine, biomineralization, and BMP-2 immobilization for potential bone tissue applications

Three-dimensional (3D) bioprinting is a free-form fabrication technique enabling fine feature control for tissue engineering applications. Especially, 3D scaffolds capable of supporting cell attachment, proliferation, and osteogenic differentiation are a prerequisite for bone tissue regeneration. Herein, we elaborated this approach to produce a 3D polycaprolactone (PCL) scaffold with long-term osteogenic activity. Specifically, we coated polydopamine (PDA) on 3D PCL scaffolds, subsequently deposited hydroxyapatite (HA) nanoparticles via biomimetic mineralization, and finally immobilized bone morphogenetic protein-2 (BMP-2). Material properties were characterized and compared with various 3D scaffolds, including PCL, PDA-coated PCL (PCL/PDA), and PDA-coated and HA-deposited PCL (PCL/PDA/HA). In vitro cell culture studies with osteoblasts revealed that the PCL/PDA/HA scaffolds immobilized with BMP-2 showed long-term retention of BMP-2 (for up to 21 days) and significantly increased osteoblast proliferation and osteogenic differentiation, as evidenced by metabolic activity, alkaline phosphatase activity, and calcium deposition. We believe that this multifunctional osteogenic 3D scaffold will be useful for bone tissue engineering applications.

Intrinsic Cellular Responses of Human Wharton's Jelly Mesenchymal Stem Cells Influenced by O2-Plasma-Modified and Unmodified Surface of Alkaline-Hydrolyzed 2D and 3D PCL Scaffolds.

Polycaprolactone (PCL), a hydrophobic-degradable polyester, has been widely investigated and extensively developed, to increase the biocompatibility for tissue engineering. This research was the first trial to evaluate the intrinsic biological responses of human Wharton’s Jelly Mesenchymal Stem Cells (hWJMSCs) cultured on alkaline hydrolysis and low-pressure oxygen plasma modified 2D and 3D PCL scaffolds, without adding any differentiation inducers; this has not been reported before. Four types of the substrate were newly established: 2D plasma-treated PCL (2D-TP), 2D non-plasma-treated PCL (2D-NP), 3D plasma-treated PCL (3D-TP), and 3D non-plasma-treated PCL (3D-NP). Physicochemical characterization revealed that only plasma-treated PCL scaffolds significantly increased the hydrophilicity and % oxygen/carbon ratio on the surfaces. The RMS roughness of 3D was higher than 2D conformation, whilst the plasma-treated surfaces were rougher than the non-plasma treated ones. The cytocompatibility test demonstrated that the 2D PCLs enhanced the initial cell attachment in comparison to the 3Ds, indicated by a higher expression of focal adhesion kinase. Meanwhile, the 3Ds promoted cell proliferation and migration as evidence of higher cyclin-A expression and filopodial protrusion, respectively. The 3Ds potentially protected the cell from apoptosis/necrosis but also altered the pluripotency/differentiation-related gene expression. In summary, the different configuration and surface properties of PCL scaffolds displayed the significant potential and effectiveness for facilitating stem cell growth and differentiation in vitro. The cell–substrate interactions on modified surface PCL may provide some information which could be further applied in substrate architecture for stem cell accommodation in cell delivery system for tissue repair.

Fabrication and characterization of porous polycaprolactone scaffold via extrusion-based cryogenic 3D printing for tissue engineering

Earlier reports of fabricating 3D porous PCL scaffolds for tissue engineering applications were overshadowed by several limitations such as additional molds cost, relatively low efficiency, and lacking process control. In present study, combined extrusion-based cryogenic 3D printing (ECP) (−20 °C) and subsequent freeze-drying approaches were employed to facilely fabricate polycaprolactone (PCL) scaffolds, with high porosity and fidelity. Freeze-drying caused shrinkage of the scaffolds along X, Y, and Z-axes to some extent. The porosities of CP600, CP800, and CP1000 were found to be 64.0 ± 1.2%, 70.1 ± 1.3%, and 74.3 ± 0.6%, respectively. The fabricated scaffolds were characterized for various structural features and compared with the ones fabricated through traditional extrusion-based melt 3D printing (EMP). The crystallinity of PCL in ECP scaffolds was lower (57.1 ± 2.2%) than EMP scaffolds (69.8 ± 1.3%). The ECP scaffolds showed high alkaline degradation, but low compression properties. The ECP scaffolds promoted the adhesion and proliferation of MCT3T-E1 cells with well-spread morphology on the porous filaments. Together, these features justify the suitability of printed PCL scaffolds for potential TE applications.

The Effect of Endothelial Cells on UVB-induced DNA Damage and Transformation of Keratinocytes In 3D Polycaprolactone Scaffold Co-culture System.

Nitric oxide ( ) plays an important role in the regulation of redox balance in keratinocytes post-UVB exposure. Since endothelial cells releases for a prolonged time post-UVB, we determined whether human umbilical vein endothelial cells (HUVEC) could have an effect on UVB-induced DNA damage and transformation of their adjacent keratinocytes (HaCaT) using a 3D cell co-culturing system. Our data show that the levels of DNA breaks and/or cyclobutane pyrimidine dimer (CPD) along with γH2AX are higher in the co-cultured than in the mono-cultured keratinocytes post-UVB. The level in the co-cultured cells is increased approximately 3-fold more than in mono-cultured HaCaT cells within 1-hour post-UVB but then is reduced quickly in co-cultured HaCaT cells comparing to mono-cultured cells from 6 to 24 h post-UVB. However, the peroxynitrite (ONOO- ) level is higher in the co-cultured than in the mono-cultured HaCaT cells in whole period post-UVB. Furthermore, while expression level of inducible nitric oxide synthase (iNOS) is increased, the ratio of coupled/uncoupled eNOS is reduced in co-cultured HaCaT cells compared to mono-cultured HaCaT cells. Finally, the co-cultured cells have a significantly increased transformation efficiency after repeating UVB exposure compared to mono-culture HaCaT cells. Our results suggest that endothelial cells could enhance /ONOO- imbalance and promote transformation of adjacent keratinocytes.

Effect of oxygen plasma etching on pore size-controlled 3D polycaprolactone scaffolds for enhancing the early new bone formation in rabbit calvaria.

This study was to investigate the effects of O2 plasma-etching of the 3D polycaprolactone (PCL) scaffold surface on preosteoblast cell proliferation and differentiation, and early new bone formation. The PCL scaffolds were fabricated by 3D printing technique. After O2 plasma treatment, surface characterizations were examined by scanning electron microscopy, atomic force microscopy, and contact angle. MTT assay was used to determine cell proliferation. To investigate the early new bone formation, rabbits were sacrificed at 2 weeks for histological analyses. As the O2 plasma etching time is increased, roughness and hydrophilicity of the PCL scaffold surface increased. The cell proliferation and differentiation on plasma-etched samples was significantly increased than on untreated samples. At 2 weeks, early new bone formation in O2 plasma-etched PCL scaffolds was the higher than that of untreated scaffolds. The O2 plasma-etched PCL scaffolds showed increased preosteoblast differentiation as well as increased new bone formation.

Functionalization of PCL-3D electrospun nanofibrous scaffolds for improved BMP2-induced bone formation

Bone morphogenic protein 2 (BMP2) is a key growth factor for bone regeneration, possessing FDA approval for orthopedic applications. BMP2 is often required in supratherapeutic doses clinically, yielding adverse side effects and substantial treatment costs. Considering the crucial role of materials for BMPs delivery and cell osteogenic differentiation, we devote to engineering an innovative bone-matrix mimicking niche to improve low dose of BMP2-induced bone formation. Our previous work describes a novel technique, named thermally induced nanofiber self-agglomeration (TISA), for generating 3D electrospun nanofibrous (NF) polycaprolactone (PCL) scaffolds. TISA process could readily blend PCL with PLA, leading to increased osteogenic capabilities in vitro, however, these bio-inert synthetic polymers produced limited BMP2-induced bone formation in vivo. We therefore hypothesize that functionalization of NF 3D PCL scaffolds with bone-like hydroxyapatite (HA) and BMP2 signaling activator phenamil will provide a favorable osteogenic niche for bone formation at low doses of BMP2. Compared to PCL-3D scaffolds, PCL/HA-3D scaffolds demonstrated synergistically enhanced osteogenic differentiation capabilities of C2C12 cells with phenamil. Importantly, in vivo studies showed that this synergism was able to generate significantly increased new bone in an ectopic mouse model, suggesting that PCL/HA-3D scaffolds act as a favorable synthetic extracellular matrix for bone regeneration.

Cell Proliferation on Macro/Nano Surface Structure and Collagen Immobilization of 3D Polycaprolactone Scaffolds.

In this study, 3D polycaprolactone (PCL) scaffolds were fabricated by 3D printing technique. The macro/nano morphology of, 3D PCL scaffolds surface was etched with oxygen plasma. Acrylic acid (AA) plasma-polymerization was performed to functionalize the macro/nano surface with carboxyl groups and then collagen was immobilized with plasma-polymerized 3D PCL scaffolds. After O2 plasma and AA plasma-polymerization, contact angles were decreased. The FE-SEM and AFM results showed that O2 plasma is increased the surface roughness. The MTT assay results showed that proliferation of the M3CT3-E1 cells increased on the oxygen plasma treated and collagen immobilized 3D PCL scaffolds.

Preparation of mussel-inspired 3D polycaprolactone scaffolds and grafted with rhBMP-2 for bone tissue engineering

Event Abstract Back to Event Preparation of mussel-inspired 3D polycaprolactone scaffolds and grafted with rhBMP-2 for bone tissue engineering Sang Jin Lee1, 2, Wan-Kyu Ko1, Na Re Ko1, Min Heo1, Su A Park2 and Il Keun Kwon1 1 Kyung Hee University, Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, Korea 2 Korea Institute of Machinery and Materials, Department of Nature-Inspired Nanoconvergence Systems, Korea Introduction: In the tissue engineering area, the bio-compatible scaffold for bone tissue regeneration should provide not only surface of excellent hydrophilicity for cell attachment onto substrate, but also binding an efficiency of bio-active molecule such as growth factor to promote a differentiation of cells. In this work, thus, we prepared a recombinant human bone morphogenic protein-2 (rhBMP2) grafting on three-dimensional (3D) polycaprolactone scaffold (PCLS)[1],[2] using polydopamine (DOPA) chemistry. Material and Method: The DOPA coated PCL scaffold was characterized by contact angle, water uptake, and x-ray photoelectron spectroscopy (XPS) test to certify whether coated DOPA or not. In order to systematize the loading efficiency of rhBMP2, we examined the releasing test for 21 days. In vitro cell study, pre-osteoblast like MC3T3-E1 cells were seeded on PCL scaffold (PCLS), DOPA coated PCL scaffold (PCLSD), and varying concentration of rhBMP2 grafted onto scaffold PCLSD 100, PCLSD 500 (100ng/ml, 500ng/ml loaded), respectively. They were analyzed by cell proliferation, alkaline phosphatase activity, and real time polymerase chain reaction in order to verify an osteogenic activity of cells. Results and Discussion: In results, we demonstrated that our fabricated a hybrid scaffold well coated with DOPA, and enable both only high loading efficiency and sustained release of rhBMP2. In the in vitro results, the developed 3D porous scaffold promoted the pre-osteoblast attachment, cell proliferation. Moreover they encouraged an osteoconductivity compared to rhBMP2-free scaffold. Conclusion: All of results indicated that our manufactured 3D porous scaffold would be useful and potential application for bone tissue engineering field.

Photolithography and micromolding techniques for the realization of 3D polycaprolactone scaffolds for tissue engineering applications

Material science, cell biology, and engineering are all part of the research field of tissue engineering. It is the application of knowledge, methods and instrumentations of engineering and life science to the development of biocompatible solutions for repair and/or replace tissues and damaged organs.Last generation microfabrication technologies utilizing natural and synthetic biomaterials allow the realization of scaffolds resembling tissue-like structures as skin, brain, bones, muscles, cartilage and blood vessels.In this work we describe an effective and simple micromolding fabrication process allowing the realization of 3D polycaprolactone (PCL) scaffold for human neural stem cells (hNSC) culture. Scanning Electron Microscopy has been used to investigate the micro and nano features characterizing the surface of the device. Immunofluorescence analysis showed how, after seeding cells onto the substrate, healthy astrocytes grew up in a well-organized 3D network. Thus, we proposed this effective fabrication method for the production of nanopatterned PCL pillared scaffold providing a biomimetic environment for the growth of hNSC, a promising and efficient means for future applications in tissue engineering and regenerative medicine.

폴리머 적층 시스템을 이용한 중공축 형상 인공지지체의 제작 및 비교 분석

Tissue engineering scaffolds depend not only on the cellular activity of biomaterials but also on the microstructures. 3D printing has the potential to fabricate complex three-dimensional (3D) structures with inter / outer controlled microstructures due to its use in computer-aided design (CAD). A polymer deposition system (PDS) using synthetic biopolymer is an effective technique for the fabrication of 3D scaffolds in bone tissue engineering applications. Polycaprolactone (PCL) has been used extensively as scaffolding biomaterials to regenerate a new tissue. 300 / Solid Shaft, 300 / Hollow Shaft, 700 / Solid Shaft, and 700 / Hollow Shaft scaffolds with pore sizes of 300 and 700 µm and structures of Solid Shaft and Hollow Shaft were fabricated by PDS. The dimensions of the 3D PCL scaffolds were 7.0×7.0×3.6 mm3. The compressive strength of the 3D PCL scaffolds was measured by compression test machine. In addition, the in-vitro cell adhesion and proliferation results of human osteosarcoma (MG63 cell line) cells seeded on scaffolds were evaluated by a cell counting kit-8 assay. These results provide design parameters for bone tissue engineering scaffolds.

Novel 3D polycaprolactone scaffold for ridge preservation--a pilot randomised controlled clinical trial.

This pilot randomised controlled clinical trial aimed to evaluate the feasibility and effectiveness of using a polycaprolactone (PCL) scaffold in fresh extraction sockets for ridge preservation. The hypothesis was that the insertion of a 3D bioresorbable PCL scaffold in fresh extraction sockets allowed for normal bone healing and better maintenance of ridge dimensions after 6 months as compared to extraction sockets without the scaffold. Thirteen patients were randomised to either the test group (N = 6) where a PCL scaffold was inserted in the tooth socket after extraction or the control group (N = 7) where no space filler was used. Alveolar ridge height and width measurements were made at baseline and 6 months post-extraction, for the evaluation of bone resorption. At 6 months, a core of bone was trephined out from the healed ridge for microcomputed tomographic (micro CT) and histological analyses, immediately before Stage I dental implant surgery. Stage II dental implant surgery was performed 4-6 months later. There was less vertical ridge resorption in the test group compared to the control group, and the difference was statistically significant in the mesio-buccal aspect (P = 0.008). Micro CT and histological observations showed mainly mineralised bone formation in both groups, except for one specimen in the test group. The insertion of a 3D bioresorbable PCL scaffold in fresh extraction sockets allowed for normal bone healing, and there was better maintenance of ridge height after 6 months as compared to extraction sockets without the scaffold.

Protein adsorption and cell adhesion on three-dimensional polycaprolactone scaffolds with respect to plasma modification by etching and deposition techniques

In this work, protein adsorption and cell adhesion on three-dimensional (3D) polycaprolactone (PCL) scaffolds treated by plasma etching and deposition were performed. The 3D PCL scaffold used as a substrate of a bone tissue was fabricated by recent rapid prototype techniques. To increase surface properties, such as hydrophilicity, roughness, and surface chemistry, through good protein adhesion on scaffolds, oxygen (O2) plasma etching and acrylic acid or allyamine plasma deposition were performed on the 3D PCL scaffolds. The O2 plasma etching induced the formation of random nanoporous structures on the roughened surfaces of the 3D PCL scaffolds. The plasma deposition with acrylic acid and allyamine induced the chemical modification for introducing a functional group. The protein adsorption increased on the O2 plasma-etched surface compared with an untreated 3D PCL scaffold. MC3T3-E1 cells adhered bioactively on the etched and deposited surface compared with the untreated surface. The present plasma modification might be sought as an effective technique for enhancing protein adsorption and cell adhesion.

Collagen grafted 3D polycaprolactone scaffolds for enhanced cartilage regeneration.

Current surgical and repair treatments for articular cartilage defects still do not give satisfactory long-term results. Scaffold-based tissue engineering is the subject of much intensive interest. However, one major hurdle is that it is unable to accurately replicate the internal three dimensional (3D) microstructure of cartilage. In this work, a novel electrohydrodynamic printing (E-Jetting) technique was employed to fabricate 3D polycaprolactone (PCL) scaffolds, followed by collagen grafting mediated by polydopamine. Surface topography, chemical composition, and wettability of the scaffolds before and after surface functionalization were characterized. Porcine chondrocytes were seeded within the scaffolds for chondrogenesis evaluation. The results showed that a 3D PCL scaffold with controlled fibre diameter, orientation, and pore size was fabricated by the E-Jetting system. The surface functionalization made the PCL scaffold hydrophilic and favourable for cell attachment. The chondrocytes maintained their healthy phenotypes within the collagen grafted PCL scaffold. The increased production of sulfated glycosaminoglycan and highly expressed collagen type II demonstrated that collagen had a positive role in stimulating chondrogenesis and the collagen grafted PCL scaffold was effective in cartilage regeneration.

A Three-Dimensional Polycaprolactone Scaffold Combined with a Drug Delivery System Consisting of Electrospun Nanofibers

A new three-dimensional (3D) scaffold containing a functional drug delivery system (DDS) consisting of electrospun micro/nanofibers is proposed. In the DDS scaffold, a core-shell laminated, structured, electrospun mat of hydrophobic polycaprolactone (PCL) and hydrophilic poly(ethylene oxide) (PEO)/rhodamine-B fibers was embedded in the normal 3D PCL scaffold, which was fabricated by a melt-plotting system. Rhodamine release from the scaffold was controlled physically by the thickness change of the PCL layer, and initial burst in drug release was eliminated by an appropriate thickness of the PCL layer. This simple technique may be useful in fabricating DDS-functional scaffolds for the clinical areas not only of bone and skin regeneration, but also of other tissue regeneration areas, regardless of the degradation rate of the structural scaffold.

The interaction between bone marrow stromal cells and RGD-modified three-dimensional porous polycaprolactone scaffolds

We previously established a simple method to immobilize the Arg-Gly-Asp (RGD) peptide on polycaprolactone (PCL) two-dimensional film surfaces that significantly improved bone marrow stromal cell (BMSC) adhesion to these films. The current work extends this modification strategy to three-dimensional (3D) PCL scaffolds to investigate BMSC attachment, cellular distribution and cellularity, signal transduction and survival on the modified PCL scaffold compared to those on the untreated ones. The results demonstrated that treatment of 3D PCL scaffold surfaces with 1,6-hexanediamine introduced the amino functional groups onto the porous PCL scaffold homogenously as detected by a ninhydrin staining method. Followed by the cross-linking reaction, RGDC peptide was successfully immobilized on the surface of PCL scaffold. Although the static seeding method used in this study caused heterogeneous cell distribution, the RGD-modified PCL scaffold still demonstrated the improved BMSC attachment and cellular distribution in the scaffold. More importantly, the integrin-mediated signal transduction FAK–PI3K–Akt pathway was significantly up-regulated by RGD modification and a subsequent increase in cell survival and growth was found in the modified scaffold. The present study introduces an easy method to immobilize RGD peptide on the 3D porous PCL scaffold and provides further evidence that modification of 3D PCL scaffolds with RGD peptides elicits specific cellular responses and improves the final cell–biomaterial interaction.

3D polycaprolactone scaffolds with controlled pore structure using a rapid prototyping system

Designing a three-dimensional (3-D) ideal scaffold has been one of the main goals in biomaterials and tissue engineering, and various mechanical techniques have been applied to fabricate biomedical scaffolds used for soft and hard tissue regeneration. Scaffolds should be biodegradable and biocompatible, provide temporary support for cell growth to allow cell adhesion, and consist of a defined structure that can be formed into customized shapes by a computer-aided design system. This versatility in preparing scaffolds gives us the opportunity to use rapid prototyping devices to fabricate polymeric scaffolds. In this study, we fabricated polycaprolactone scaffolds with interconnecting pores using a 3-D melt plotting system and compared the plotted scaffolds to those made by salt leaching. Scanning electron microscopy, a laser scanning microscope, micro-computed tomography, and dynamic mechanical analysis were used to characterize the geometry and mechanical properties of the resulting scaffolds and morphology of attached cells. The plotted scaffolds had the obvious advantage that their mechanical properties could be easily manipulated by adjusting the scaffold geometry. In addition, the plotted scaffolds provided more opportunity for cells to expand between the strands of the scaffold compared to the salt-leached scaffold.