Maryam Zarghami Dehaghani,1 Farrokh Yousefi,2 Babak Bagheri,3 Farzad Seidi,1 Amin Hamed Mashhadzadeh,4 Navid Rabiee,5 Payam Zarrintaj,6 Ebrahim Mostafavi,7,8 Mohammad Reza Saeb,4 Yeu-Chun Kim3 1Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources and Joint International Research Lab of Lignocellulosic Functional Materials, Nanjing Forestry University, Nanjing, 210037, Peopleâs Republic of China; 2Department of Physics, University of Zanjan, Zanjan, 45195-313, Iran; 3Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea; 4Center of Excellence in Electrochemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran; 5Department of Chemistry, Sharif University of Technology, Tehran, 11155-3516, Iran; 6School of Chemical Engineering, Oklahoma State University, Stillwater, OK, 74078, USA; 7Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA; 8Department of Medicine, Stanford University School of Medicine, Stanford, CA, USACorrespondence: Ebrahim MostafaviStanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USAEmail ebimsv@stanford.eduAmin Hamed MashhadzadehCenter of Excellence in Electrochemistry, School of Chemistry, College of Science, University of Tehran, Tehran, 14155-6455, IranEmail amin.hamed.m@gmail.comIntroduction: Antimicrobial peptides are potential therapeutics as anti-bacteria, anti-viruses, anti-fungi, or anticancers. However, they suffer from a short half-life and drug resistance which limit their long-term clinical usage.Methods: Herein, we captured the encapsulation of antimicrobial peptide HA-FD-13 into boron nitride nanotube (BNNT) (20,20) and its release due to subsequent insertion of BNNT (14,14) with molecular dynamics simulation.Results: The peptide-BNNT (20,20) van der Waals (vdW) interaction energy decreased to â 270 kcal·molâ 1 at the end of the simulation (15 ns). However, during the period of 0.2â 1.8 ns, when half of the peptide was inside the nanotube, the encapsulation was paused due to an energy barrier in the vicinity of BNNT and subsequently the external intervention, such that the self-adjustment of the peptide allowed full insertion. The free energy of the encapsulation process was â 200.12 kcal·molâ 1, suggesting that the insertion procedure occurred spontaneously.Discussion: Once the BNNT (14,14) entered into the BNNT (20,20), the peptide was completely released after 83.8 ps. This revealed that the vdW interaction between the BNNT (14,14) and BNNT (20,20) was stronger than between BNNT (20,20) and the peptide; therefore, the BNNT (14,14) could act as a piston pushing the peptide outside the BNNT (20,20). Moreover, the sudden drop in the vdW energy between nanotubes to the value of the â 1300 Kcal·molâ 1 confirmed the self-insertion of the BNNT (14,14) into the BNNT (20,20) and correspondingly the release of the peptide.Keywords: drug delivery, boron nitride nanotubes, molecular dynamics simulation, drug release, antimicrobial peptide