TY - JOUR
T1 - Delivery of agents into articular cartilage with electric spark-induced sound waves
AU - Pérez, Alejandro García
AU - Nieminen, Heikki J.
AU - Finnilä, Mikko
AU - Salmi, Ari
AU - Pritzker, Kenneth P.H.
AU - Lampsijärvi, Eetu
AU - Paulin, Tor
AU - Airaksinen, Anu J.
AU - Saarakkala, Simo
AU - Hæggström, Edward
PY - 2018/10/16
Y1 - 2018/10/16
N2 - Localized delivery of drugs into articular cartilage (AC) may facilitate the development of novel therapies to treat osteoarthritis (OA). We investigated the potential of spark-gap-generated sound to deliver a drug surrogate, i.e., methylene blue (MB), into AC. In vitro experiments exposed bovine AC samples to either simultaneous sonication and immersion in MB (Treatment 1; n = 10), immersion in MB after sonication (Control 1; n = 10), solely immersion in MB (Control 2; n = 10), or neither sonication nor immersion in MB (Control 3; n = 10). The sonication protocol consisted of 1,000 spark-gap -generated pulses. Delivery of MB into AC was estimated from optical absorbance in transmission light microscopy. Optical absorbance was significantly greater in the treatment group up to 900 μm depth from AC surface as compared to all controls. Field emission scanning electron microscopy (FESEM), histological analysis, and digital densitometry (DD) of sonicated (n = 6) and non-sonicated (n = 6) samples showed no evidence of sonication-induced changes in proteoglycan content or collagen structure. Consequently, spark-gap -generated sound may offer a solution for localized drug delivery into AC in a non-destructive fashion. Further research on this method may contribute to OA drug therapies.
AB - Localized delivery of drugs into articular cartilage (AC) may facilitate the development of novel therapies to treat osteoarthritis (OA). We investigated the potential of spark-gap-generated sound to deliver a drug surrogate, i.e., methylene blue (MB), into AC. In vitro experiments exposed bovine AC samples to either simultaneous sonication and immersion in MB (Treatment 1; n = 10), immersion in MB after sonication (Control 1; n = 10), solely immersion in MB (Control 2; n = 10), or neither sonication nor immersion in MB (Control 3; n = 10). The sonication protocol consisted of 1,000 spark-gap -generated pulses. Delivery of MB into AC was estimated from optical absorbance in transmission light microscopy. Optical absorbance was significantly greater in the treatment group up to 900 μm depth from AC surface as compared to all controls. Field emission scanning electron microscopy (FESEM), histological analysis, and digital densitometry (DD) of sonicated (n = 6) and non-sonicated (n = 6) samples showed no evidence of sonication-induced changes in proteoglycan content or collagen structure. Consequently, spark-gap -generated sound may offer a solution for localized drug delivery into AC in a non-destructive fashion. Further research on this method may contribute to OA drug therapies.
KW - Cartilage
KW - Drug delivery
KW - Electric sparks
KW - Osteoarthritis therapies
KW - Sound
KW - Ultrasound
UR - http://www.scopus.com/inward/record.url?scp=85055124844&partnerID=8YFLogxK
U2 - 10.3389/fphy.2018.00116
DO - 10.3389/fphy.2018.00116
M3 - Article
AN - SCOPUS:85055124844
VL - 6
SP - 1
EP - 7
JO - Frontiers in Physics
JF - Frontiers in Physics
SN - 2296-424X
IS - OCT
M1 - 116
ER -