Lanthanides-Substituted Hydroxyapatite/Aloe vera Composite Coated Titanium Plate for Bone Tissue Regeneration

Selvakani Prabakaran,1 Mariappan Rajan,1 Changwei Lv,2 Guolin Meng3 1Biomaterials in Medicinal Chemistry Laboratory, Department of Natural Products Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625021, India; 2Department of Orthopaedics, The Affiliated Hospital of Northwest University, Xi’an No.3 Hospital, Xi’an 710018, Mainland China; 3Orthopaedic Department of Xijing Hospital of the Fourth Military Medical University, Xi’an, Shaanxi, 710032, Mainland ChinaCorrespondence: Changwei Lv Department of OrthopaedicsThe Affiliated Hospital of Northwest University, Xi’an No.3 Hospital, Xi’an 710018, Mainland ChinaEmail lucwei76@sina.comPurpose: To develop the surface-treated metal implant with highly encouraged positive properties, including high anti-corrosiveness, bio-activeness and bio-compatibleness for orthopedic applications.Methods: In this work, the surface of commercially pure titanium (Ti) metal was treated with bio-compatible polydopamine (PD) by merely immersing the Ti plate in PD solution. The composite of trivalent lanthanide minerals (La3+, Ce3+ and Gd3+)-substituted hydroxyapatite (MHAP) with Aloe vera (AV) gel was prepared and coated on the PD-Ti plate by electrophoretic deposition (EPD) method. The choice of trivalent lanthanide ions is based on their bio-compatible nature and bone-seeking properties. The formation of the PD layer, composites, and composite coatings on Ti plate and PD-Ti surface was confirmed by FT-IR, XRD, SEM and HR-TEM observations. In-vitro assessments such as osteoblasts like MG-63 cell viability, alkaline phosphatase activity and mineralization ability of the MHAP/AV composite were tested, and the composite-coated plate was implanted into a rat bone defect model for in-vivo bone regeneration studies.Results: The coating ability of the MHAP/AV composite was highly preferred to PD-treated Ti plate than an untreated Ti plate due to the metal absorption ability of PD. This was confirmed by SEM analysis. The in-vitro and in-vivo studies show the better osteogenic ability of MHAP/AV composite at 14th day and 4th week of an experimental period, respectively.Conclusion: The osteoblast ability of the fabricated device without producing any adverse effect in the rat model recommends that the fabricated device would serve as a better platform on the hard tissue regeneration for load-bearing applications of orthopedics.Keywords: bio-compatible, electrophoretic deposition, hydroxyapatite, mussel adhesive protein, polydopamine, surface treatment