Acknowledgements This study was supported by a grant from the Korea Wellness technology R D Project, 2-Hydroxy-4-methoxybenzaldehydeReferences Ministry of Overall health Welfare, Republic of Korea (A120822). It was regarded that monolayer PLGA membrane utilized in this PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/25432023 study was behind in biocompatibility and retention period than collagen membrane.T HA stimulated proliferation of osteoblast by means of in vitro study, and Park  et al. reported thatmore bone formation was observed within the HA applied PLGA membrane than in either PLGA or collagen membrane in white rat calvarial defects. Premature degradation of the collagen membrane partially occurred at four weeks, but all round contour was sustained. Much more substantial premature breakdown of membrane accompanied by sporadic proliferation of inflammatory cell also occurred in monolayer PLGA membrane group. Jung  et al. reported that the outcome of PLGA membrane degradation was worse than the collagen membrane because of its accelerated breakdown. It was considered that monolayer PLGA membrane applied within this PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/25432023 study was behind in biocompatibility and retention period than collagen membrane. However, within the three-layer PLGA membrane, HA hydrogel was formed in fibrous capsule-like structure supporting the entire contour of membrane and preventing infiltration of external organism throughout the period of observation. In other words, the HA hydrogel reinforced three-layer PLGA membrane was thought of that it showed improved retention period and cell occlusion. Having said that, in comparison 5 HA hydrogel with ten HA hydrogel, no definite difference was observed in biocompatibility and retention period with the membrane. Afterwards, additional experimental observations should be conducted by revision of study design and style, such as expansion of experimental populations, modification of right concentration of HA hydrogel, fabrication of 3-layer scaffolds and long-term observation of healing group.Conclusion This study investigated the probability of applications from the three-layer PLGA membrane to the membrane by using distinct concentrations of HA hydrogel in/on the PLGA membrane. Unique level of inflammatory response was observed in the newly developed three-layer PLGA membrane also because the fantastic property in cell occlusion. From the benefits, the HA hydrogel reinforced three-layer PLGA membrane had longer retention period than collagen membrane and monolayer PLGA membrane had in rabbit calvarial defects. Further study is below progress to enhance the inflammatory response observed in this study.Availability of supporting data The information sets supporting the outcomes of this short article are included inside the short article.You et al. Biomaterials Research 2014, 18:12 http://www.biomaterialsres.com/content/18/1/Page 7 ofCompeting interests The authors declare that they have no competing interests. Authors' contributions HY carried out thesis writing, and HY and JYP performed animal study. EUL, HCL, JSL, UIJ and SHC carried out supervision and building for thesis. YKK proofread the manuscript. BCK and ISN developed experimental materials. And, ISN, UIJ, SHC are co-corresponding author. All authors study and authorized the final manuscript. Acknowledgements This study was supported by a grant with the Korea Well being technologies R D Project, Ministry of Well being Welfare, Republic of Korea (A120822). Author specifics 1 Department of Periodontology, Investigation Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul 120-752, Korea. 2 Department of Chemical and Biomolecular Engineering, PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/25957400 Seoul 139-743, Korea. 3Convergence Institute of Biomedical Engineering and Biomaterials, Seoul National University of Science and Technologies, Seoul 139-743, Korea.