Exploitation of a novel polysaccharide nanogel cross-linking membrane for guided bone regeneration (GBR)

Abstract

Cholesterol-bearing pullulan (CHP) nanogel is a synthetic degradable biomaterial for drug delivery with high biocompatibility. Guided bone regeneration (GBR) is a bone augmentation technique in which a membrane is used to create and keep a secluded regenerative space. The purpose of the present study was to evaluate the effects of the novel CHP nanogel membrane in GBR. Thirty-six adult Wistar rats were used and bilaterally symmetrical full-thickness parietal bone defects of 5 mm diameter were created with a bone trephine burr. Each defect was covered with the collagen membrane or the CHP nanogel membrane or untreated without any membrane. The animals were sacrificed at 2, 4 and 8 weeks and analysed radiologically and histologically. Furthermore, after incubating human serum with CHP nanogel or collagen, the amount of PDGF in the serum was measured using ELISA. New bone formation in terms of bone volume was higher in the nanogel group than in the control or collagen groups at 2 and 4 weeks. At 8 weeks, both membrane groups showed higher bone volumes than the control group. Notably, the newly-formed bone in the bone defect in the nanogel group was uniform and histologically indistinguishable from the original bone, whereas in the collagen group the new bone showed an irregular structure that was completely different from the original bone. After incubating with CHP nanogel, the amount of PDGF in the serum decreased significantly. CHP nanogel GBR membrane favourably stimulated bone regeneration, in which a unique characteristic of CHP nanogel, the storage of endogenous growth factors, was likely implicated.

Guided bone regeneration using a hydrophilic membrane made of unsintered hydroxyapatite and poly(L-lactic acid) in a rat bone-defect model

“…Thus, resorbable GBR membranes are more desirable. Bovine or porcine collagen has been used as a material for resorbable GBR membranes 7,[14][15][16][17][18][19] ; however, although collagen is a highly biocompatible major matrix protein, the risk of infection with known or unknown diseases from the source animals cannot be completely eliminated, because of the physicochemically mild collagen extraction procedure [20][21][22] . An unfavorable immune reaction to the heterogeneous protein, although rare, is another concern regarding this material.…”

Lateral Bone Window Closing Technique with Poly‐L‐Lactic Acid (PLLA) Membrane in the Augmentation of the Maxillary Sinus without Grafting Material: Evaluation of Bone Healing in a Rabbit Model

“…Collagen membranes have been applied for guided tissue regeneration and GBR. However, the capacity of collagen membranes to develop unknown infections and unfavorable immune responses because of the presence of animal‐derived biomaterials cannot be denied …”

“…However, the capacity of collagen membranes to develop unknown infections and unfavorable immune responses because of the presence of animal-derived biomaterials cannot be denied. [21][22][23] PLLA consists entirely of polymerized L-lactic acid, which does not trigger the infections and immune responses characteristic of animal-derived biomaterials. The use of PLLA as a biomedical material has been widely studied in the areas of tissue engineering, bone healing materials, and drug delivery because of its nonantigenicity, reasonably good mechanical properties, biodegradability, and biocompatibility.…”

Effects of a polysaccharide nanogel-crosslinked membrane on wound healing

“…Recently, a new method, termed nanogel tectonics, was proposed to construct hydrogel materials with a hierarchical structure . By this technology, the nanogel‐crosslinked (NanoClik) gel was synthesized using self‐assembled CHP nanogels as building blocks and was applied as a scaffold in tissue engineering, for example, bone regeneration …”

“…21 By this technology, the nanogel-crosslinked (NanoClik) gel was synthesized using self-assembled CHP nanogels as building blocks and was applied as a scaffold in tissue engineering, for example, bone regeneration. 22,23 To improve the properties of the nanogel system for wound healing, we modified the "NanoClik membrane" with crosslinking and by combining it with a silicone sheet. The Correspondence to: Hiroki Maeda; e-mail: maedirm@tmd.ac.jp purpose of the present study was to examine whether this "NanoClik membrane" is effective in wound healing.…”