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Moatti A, Connard S, De Britto N, Dunn WA, Rastogi S, Rai M, Schnabel LV, Ligler FS, Hutson KA, Fitzpatrick DC, Salt A, Zdanski CJ, Greenbaum A. Surgical procedure of intratympanic injection and inner ear pharmacokinetics simulation in domestic pigs. Front Pharmacol 2024; 15:1348172. [PMID: 38344174 PMCID: PMC10853450 DOI: 10.3389/fphar.2024.1348172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/12/2024] [Indexed: 03/17/2024] Open
Abstract
Introduction: One major obstacle in validating drugs for the treatment or prevention of hearing loss is the limited data available on the distribution and concentration of drugs in the human inner ear. Although small animal models offer some insights into inner ear pharmacokinetics, their smaller organ size and different barrier (round window membrane) permeabilities compared to humans can complicate study interpretation. Therefore, developing a reliable large animal model for inner ear drug delivery is crucial. The inner and middle ear anatomy of domestic pigs closely resembles that of humans, making them promising candidates for studying inner ear pharmacokinetics. However, unlike humans, the anatomical orientation and tortuosity of the porcine external ear canal frustrates local drug delivery to the inner ear. Methods: In this study, we developed a surgical technique to access the tympanic membrane of pigs. To assess hearing pre- and post-surgery, auditory brainstem responses to click and pure tones were measured. Additionally, we performed 3D segmentation of the porcine inner ear images and used this data to simulate the diffusion of dexamethasone within the inner ear through fluid simulation software (FluidSim). Results: We have successfully delivered dexamethasone and dexamethasone sodium phosphate to the porcine inner ear via the intratympanic injection. The recorded auditory brainstem measurements revealed no adverse effects on hearing thresholds attributable to the surgery. We have also simulated the diffusion rates for dexamethasone and dexamethasone sodium phosphate into the porcine inner ear and confirmed the accuracy of the simulations using in-vivo data. Discussion: We have developed and characterized a method for conducting pharmacokinetic studies of the inner ear using pigs. This animal model closely mirrors the size of the human cochlea and the thickness of its barriers. The diffusion time and drug concentrations we reported align closely with the limited data available from human studies. Therefore, we have demonstrated the potential of using pigs as a large animal model for studying inner ear pharmacokinetics.
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Affiliation(s)
- Adele Moatti
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, North Carolina State University, Raleigh, NC, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| | - Shannon Connard
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC, United States
| | - Novietta De Britto
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, North Carolina State University, Raleigh, NC, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| | - William A. Dunn
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Srishti Rastogi
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, North Carolina State University, Raleigh, NC, United States
| | - Mani Rai
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, North Carolina State University, Raleigh, NC, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| | - Lauren V. Schnabel
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC, United States
| | - Frances S. Ligler
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
| | - Kendall A. Hutson
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Douglas C. Fitzpatrick
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Alec Salt
- Tuner Scientific, Jacksonville, IL, United States
| | - Carlton J. Zdanski
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Alon Greenbaum
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, North Carolina State University, Raleigh, NC, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
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Safa AN, Sheibani A, Baei MT, Sayyed-Alangi SZ, Tazikeh Lemeski E. Theoretical and experimental studies on sulfasalazine interactions with poly (lactic acid): Impact of hydrogen bonding and charge transfer interactions on molecular structure, electronic and optical properties. Heliyon 2024; 10:e23813. [PMID: 38205338 PMCID: PMC10776989 DOI: 10.1016/j.heliyon.2023.e23813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/10/2023] [Accepted: 12/13/2023] [Indexed: 01/12/2024] Open
Abstract
The interaction between sulfasalazine (SSZ) through different functional groups and poly (lactic acid) (PLA) in the chloroform phase was investigated in this study using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods. The binding energy and thermodynamic parameters show that the hydrogen double bond interaction between SSZ and PLA in state I (-0.71 eV) is stronger than in states II (-0.64 eV) and III (-0.51 eV). The SSZ and PLA interaction results in an enhanced dipole moment, greater solubility, and more negative values for Gibbs free energy (ΔGsolv) and energy gap (Eg). Considerable changes in absorption peaks of SSZ and PLA indicate surface adsorption of the drug (SSZ) into the carrier (PLA) in UV-Vis spectra. Theoretical UV-Vis analysis demonstrates SSZ interaction with PLA happens in the ultraviolet region with a maximum absorption peak at 380 nm, which is close to experimental UV-Vis analysis. The experimental spectra showed minimal variations in the maximum absorption wavelength, with respect to theoretical calculations. The presence of SSZ was found to cause a modification in the structure of PLA, as evidenced by both experimental and theoretical Infrared (IR) spectra.
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Affiliation(s)
- Azam Naderi Safa
- Department of Chemistry, Yazd Branch, Islamic Azad University, Yazd, Iran
| | - Ali Sheibani
- Department of Chemistry, Yazd Branch, Islamic Azad University, Yazd, Iran
| | - Mohammad T. Baei
- Department of Chemistry, Azadshahr Branch, Islamic Azad University, Azadshahr, Golestan, Iran
| | - S. Zahra Sayyed-Alangi
- Department of Chemistry, Azadshahr Branch, Islamic Azad University, Azadshahr, Golestan, Iran
| | - E. Tazikeh Lemeski
- Department of Chemistry, Gorgan Branch, Islamic Azad University, Gorgan, Iran
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