ABSTRACT
The blood-brain barrier (BBB) presents a formidable obstacle to the effective delivery of systemically administered pharmacological agents to the brain, with ~5% of candidate drugs capable of effectively penetrating the BBB. A variety of biomaterials and therapeutic delivery devices have recently been developed that facilitate drug delivery to the brain. These technologies have addressed many of the limitations imposed by the BBB by: (1) designing or modifying the physiochemical properties of therapeutic compounds to allow for transport across the BBB; (2) bypassing the BBB by administration of drugs via alternative routes; and (3) transiently disrupting the BBB (BBBD) using biophysical therapies. Here we specifically review colloidal drug carrier delivery systems, intranasal, intrathecal, and direct interstitial drug delivery methods, focused ultrasound BBBD, and pulsed electrical field induced BBBD, as well as the key features of BBB structure and function that are the mechanistic targets of these approaches. Each of these drug delivery technologies are illustrated in the context of their potential clinical applications and limitations in companion animals with naturally occurring intracranial diseases.
ABSTRACT
Luft is professor emerita, School of Lifespan Development and Educational Sciences, College of Education, Health and Human Services, Kent State University, Kent, OH. She was president of the Council on Education of the Deaf (CED) from 2018 to 2020. Fischgrund is adjunct faculty, Department of Special Education, Saint Joseph's University, Philadelphia, PA. He was CED executive director from 2012 to 2019. Eardley is the owner of Future Endeavors Consulting, Cleveland, OH. Tanner is a teacher of deaf and hard of hearing students, Pasco County (FL) Schools. Reusser is a staff interpreter, Cleveland Hearing and Speech Center. Eardley, Tanner, and Reusser were graduate assistants at Kent State University when the research for the present article was conducted.Teacher shortages and alternative licensure requirements, in combination with inconsistent state licensure regulations, suggest that not all teachers of deaf and hard of hearing students have the expertise to successfully educate their students. Most national, regional, and specialized professional accreditations do not assess DHH-specific instructional and communication proficiencies, and thus may contribute to DHH students' low achievement levels relative to those of their hearing peers. The study surveyed teaching licensure requirements across the 50 states and District of Columbia regarding compliance with federal requirements and state variations. Results showed that 39% of states did not require a DHH-specific teacher-training program; 45% did not employ a DHH-specific licensure exam. Only 25% required documentation of language/communication skills. A specialized accrediting organization, such as the Council on Education of the Deaf, could help identify well-prepared teachers to fill current and future vacancies and thereby improve DHH students' achievement.
