Polydopamine constructed interfacial molecular bridge in nano-hydroxylapatite/polycaprolactone composite scaffold
Graphical Abstract
Introduction
Polycaprolactone (PCL), a synthetic polyester-based biopolymer, has been widely served as an artificial bone scaffold material due to its acceptable cytocompatibility, bioabsorbability and processability [1], [2]. While scaffold made of single PCL material can not meet the requirements of bone defect repair due to the lack of necessary bioactivity and osteoconductive ability [3]. Hydroxylapatite (HAP) is a dominant inorganic constituent of natural bone and exhibits excellent biocompatibility, bioactivity, and osteoconduction, which is usually used as a bioactive component to endow a biopolymer with bioactivity and osteoconductive ability [4], [5]. Therefore, the combination of HAP with PCL might exhibit the great potential for bone tissue engineering applications [1], [6]. However, the interfacial bonding [7] between HAP and PCL is very weak because of the immiscible thermodynamic properties [8], resulting in the deterioration of mechanical properties [9].
In recent years, various strategies such as chemical grafting [10] and coupling agent modification [11] have been used to increase the interfacial bonding between polymer with HAP. For example, Liu et al. grafted poly bisphenol A glycidyl methacrylate (poly(Bis-GMA)) onto pre-silanized HAP crystals and found that poly(Bis-GMA) acted as a transition layer to improve the interfacial affinity between whisker and resin [12]. Qi et al. introduced silane coupling agent ethenyltrimethoxysilane (YDH171) onto the surface of HAP nanoparticles and found that YDH171 played a role of bridging and increased the interfacial interaction between between HAP and poly(lactide-co-glycolide acid)/poly(trimethylene carbonate) polymer matrix [13]. The above methods can enhance the interface bonding between HAP and polymer, while chemical grafting usually requires a complicated procedure [14], and coupling agent modification may introduce toxicity from chemical reagents [15].
Polydopamine (PDA), an adhesive material produced by the self-polymerization of dopamine (DA) [16], possesses strong adhesive properties due to its rich active amine and catechol groups [17]. Some researchers have used PDA coating to modify inorganic materials for enhancing interface bonding with polymer [18], [19]. Chung et al. used PDA to modify boehmite nanoparticles (BNPS) and then added them into epoxy resin. It was found that the amino groups in PDA could covalently react with the epoxy groups in epoxy resin matrix, thus improving the interfacial compatibility between BNPS and matrix [20]. Phua et al. introduced PDA onto the surface of clays and then added them into polyether polyurethane (PU). The results indicated that the introduced PDA could form hydrogen bonding with PU, thus improving the interfacial bonding between PU and clay [21]. In addition, PDA has been proved to be beneficial for cell adhesion and proliferation, and it can induce osteogenic differentiation [22], [23] by adsorbing extracellular matrix and related proteins [24]. Therefore, the coating of PDA on HAP might be an appropriate approach to increase the interfacial bonding with polymer matrix in composite scaffold for bone tissue engineering application.
In the present work, PDA was introduced onto HAP nanoparticles (nano-HAP) through self-polymerization of DA [25], and the modified nano-HAP were added to PCL matrix for fabricating bone scaffold via selective laser sintering (SLS). The microstructure and chemical composition of nano-HAP before and after PDA coating were studied. Tensile and compressive properties of the scaffold were investigated, the interfacial bonding mechanism was discussed. Meanwhile, the bioactivity, cytocompatibility and osteogenic ability were analyzed by mineralization, cell adhesion and alkaline phosphatase (ALP) expression experiments, respectively.
Section snippets
Materials and reagents
PCL powder with molecular weight of 100 kDa was purchased from Shenzhen Polymtek Biomaterial Co., Ltd. Nano-hydroxyapatite (nano-HAP) with particle size of approximately 100 nm was supplied by Chengdu Organic Chemicals Co., Ltd. Dopamine, tris (hydroxymethyl) aminomethane hydrochloride (Tris-HCl) and simulated body fluid (SBF) were purchased from Shanghai Sigma-Aldrich Co., Ltd.
Preparation of composite powder
Nano-HAP powder coated by PDA was produced according to Yang's research reported [26]. Briefly, Tris-HCl solution was
Results and discussion
Surface morphologies, crystal structures, lattice spacings and elements distribution of nano-HAP and P-HAP powder were characterized using SEM and TEM, as shown in Fig. 2. SEM images of HAP and P-HAP nanoparticles were provided to demonstrate their surface morphologies. As shown in Fig. 2(a, d), the nano-HAP nanoparticles were highly agglomerated, and the spherical particles were distributed in agglomerates [28]. Compared with nano-HAP nanoparticles, the dispersibility of PDA-HAP nanoparticles
Conclusions
In summary, HAP was modified by PDA and then blended into the PCL scaffold to improve mechanical properities, and P-HAP/PCL scaffold was fabricated using selective laser sintering. P-HAP displayed better dispersibility in PCL scaffold compared to pure HAP. Meanwhile, the fracture surface morphologies of P-HAP/PCL scaffolds were fine and smooth. In addition, the thermal stability of P-HAP/PCL scaffolds were improved. As a result, the tensile strength increased from 5.6 MPa for the PCL scaffolds
CRediT authorship contribution statement
Pei Feng: Conceptualization, Methodology, Software, Investigation. Xiang Qiu: Data curation, Writing – original draft preparation. Liuyimei Yang: Visualization, Investigation. Qing Liu: Supervision. Can Zhou: Software, Validation. Yongbin Hu: Writing – review & editing. Cijun Shuai: Conceptualization, Funding Acquisition, Resources, Supervision, Writing – review & editing.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgments
This work was supported by the following funds: (1) The Natural Science Foundation of China (51905553, 51935014, 82072084, 81871498); (2) Hunan Provincial Natural Science Foundation of China (2021JJ20061, 2020JJ3047, 2019JJ50588); (3) The Provincial Key Research and Development Projects of Jiangxi (20201BBE51012); (4) The Wisdom Accumulation and Talent Cultivation Project of the Third Xiangya Hosipital of Central South University (YX202001); (5) The Project of State Key Laboratory of High
References (93)
- et al.
Engineered electrospun poly (caprolactone)/polycaprolactone-g-hydroxyapatite nano-fibrous scaffold promotes human fibroblasts adhesion and proliferation
Mat. Sci. Eng. C Mater.
(2016) - et al.
Hydroxyapatite/polyurea nanocomposite: preparation and multiple performance enhancements
Compos. Part A Appl. S
(2020) - et al.
Grafting SiO2 nanoparticles on polyvinyl alcohol fibers to enhance the interfacial bonding strength with cement
Compos. Part B Eng.
(2019) - et al.
Enhanced mechanical properties and cytocompatibility of electrospun poly (l-lactide) composite fiber membranes assisted by polydopamine-coated halloysite nanotubes
Appl. Surf. Sci.
(2016) - et al.
Water-borne composite coatings using nanoparticles modified with dopamine derivatives
Thin Solid Films
(2014) - et al.
Large fuzzy biodegradable polyester microspheres with dopamine deposition enhance cell adhesion and bone regeneration in vivo
Biomaterials
(2021) - et al.
Magnetic-driven wireless electrical stimulation in a scaffold
Compos. Part B Eng.
(2022) - et al.
Application of dopamine-modified halloysite nanotubes/PVDF blend membranes for direct dyes removal from wastewater
Chem. Eng. J.
(2017) - et al.
Removal of Pb(II) from aqueous solution using hydroxyapatite/calcium silicate hydrate (HAP/CSH) composite adsorbent prepared by a phosphate recovery process
Chem. Eng. J.
(2018) - et al.
Polydopamine modified ultrathin hydroxyapatite nanosheets for anti-corrosion reinforcement in polymeric coatings
Corros. Sci.
(2021)
Investigation of polydopamine coatings by X-ray Photoelectron Spectroscopy as an effective tool for improving biomolecule conjugation
Appl. Surf. Sci.
Dopamine-modified highly porous hydroxyapatite microtube networks with efficient near-infrared photothermal effect, enhanced protein adsorption and mineralization performance
Colloid Surf. B.
Bone-like hydroxyapatite mineralization on the bio-inspired PDA nanoparticles using microwave irradiation
Surf. Interfaces
Self-healing hydroxypropyl guar gum/poly (acrylamide-co-3-acrylamidophenyl boronic acid) composite hydrogels with yield phenomenon based on dynamic PBA ester bonds and H-bond
Colloid Surf. A
Novel green synthesis of hydroxyapatite uniform nanorods via microwave-hydrothermal route using licorice root extract as template
Ceram. Int.
Recent advances in biomedical engineering of nano-hydroxyapatite including dentistry, cancer treatment and bone repair
Compos. Part B Eng.
Gold nanorods/polydopamine-capped hollow hydroxyapatite microcapsules as remotely controllable multifunctional drug delivery platform
Powder Technol.
Recent advances in biomedical engineering of nano-hydroxyapatite including dentistry, cancer treatment and bone repair
Compos. B. Eng.
Fabrication of h-BN-rGO@ PDA nanohybrids for composite coatings with enhanced anticorrosion performance
Prog. Org. Coat.
Deposition of Au nanoparticles on PDA-functionalized PVA beads as a recyclable catalyst for degradation of organic pollutants with NaBH4 in aqueous solution
J. Alloy. Compd.
Nitrogen-doped carbon-ZnO heterojunction derived from ZIF-8: a photocatalytic antibacterial strategy for scaffold
Mater. Today Nano
Mechanical properties of hydroxyapatite single crystals from nanoindentation data
J. Mech. Behav. Biomed.
Constructing the hierarchical TiN@ ZIF-8 hybrid for improving the mechanical and tribological performance of fabric composites
Compos. Commun.
Improved mechanical properties of hydroxyapatite/poly (ɛ-caprolactone) scaffolds by surface modification of hydroxyapatite
Appl. Surf. Sci.
The impact of post manufacturing treatment of functionally graded Ti6Al4V scaffolds on their surface morphology and mechanical strength
J. Mater. Res. Technol.
Rheological and mechanical properties of PVC/CaCO3 nanocomposites prepared by in situ polymerization
Polymer
A comparative study of the effects of different bioactive fillers in PLGA matrix composites and their suitability as bone substitute materials: a thermo-mechanical and in vitro investigation
J. Mech. Behav. Biomed.
Fabrication and properties of porous scaffold of zein/PCL biocomposite for bone tissue engineering
Compos. Part B Eng.
Polycaprolactone/polystyrene bioblends characterized by thermogravimetry, modulated differential scanning calorimetry and infrared photoacoustic spectroscopy and stability
Polym. Degrad. Stabil.
Characterization of hydroxyapatite from eggshell waste and polycaprolactone (PCL) composite for scaffold material
Compos. Part B Eng.
Endothelialization and patency of RGD-functionalized vascular grafts in a rabbit carotid artery model
Biomaterials
Dilemma and breakthrough of biodegradable poly-l-lactic acid in bone tissue repair
J. Mater. Res. Technol.
Poly (sodium 4-styrene sulfonate)-modified hydroxyapatite nanoparticles in zein-based scaffold as a drug carrier for vancomycin
Mat. Sci. Eng. C Mater.
A conductive network enhances nerve cell response
Addit. Manuf.
Growth factor loading on aliphatic polyester scaffolds
RSC Adv.
A metal-chelating polymer for chelating zirconium and its use in mass cytometry
Eur. Polym. J.
Enabling Indium channels for Mass Cytometry by using reinforced cyclam-based chelating polylysine
Bioconjugate Chem.
Synthesis of a metal-chelating polymer with NOTA pendants as a carrier for 64Cu, intended for radioimmunotherapy
Eur. Polym. J.
Metal-chelating polymers (MCPs) with zwitterionic pendant groups complexed to trastuzumab exhibit decreased liver accumulation compared to polyanionic MCP immunoconjugates
Biomacromolecules
Fabrication and evaluation of (PVA/HAp/PCL) bilayer composites as potential scaffolds for bone tissue regeneration application
Ceram. Int.
Fabrication of shish-kebab-structured carbon nanotube/poly (ε-caprolactone) composite nanofibers for potential tissue engineering applications
Rare Met.
Polymer fiber scaffolds for bone and cartilage tissue engineering
Adv. Funct. Mater.
3D printing of hydroxyapatite/tricalcium phosphate scaffold with hierarchical porous structure for bone regeneration
Bio Des. Manuf.
Fabrication and characterization of 3D printed biocomposite scaffolds based on PCL and zirconia nanoparticles
Bio Des. Manuf.
Transcrystalline growth of PLLA on carbon fiber grafted with nano-SiO2 towards boosting interfacial bonding in bone scaffold
Biomater. Res.
Effect of interface on mechanical properties and biodegradation of PCL HAp supramolecular nano-composites
J. Mater. Sci. Mater. M.
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