Intra-discal vancomycin-loaded PLGA microsphere injection for MRSA discitis: an experimental study.

Abstract

OBJECTIVE:

To prepare the vancomycin hydrochloride (VA)-loaded poly lactic acid-glycolic acid (PLGA) copolymer microsphere by the multiple emulsion method and evaluate its therapeutic effects on infective discitis.

METHODS:

Firstly, the particle diameter distribution, shape, encapsulation efficiency, drug-loaded dosage and release curve of VA-PLGA microspheres were evaluated in vitro. Rabbits with methicillin-resistant Staphylococcus aureus infective discitis were treated with VA-PLGA intra-discal injection. Meanwhile, VA intravenous injection, blank PLGA microspheres intra-discal injection served as controls. Thirty days later, therapeutic effects were evaluated through X-ray radiophotography, histopathological and bacteriological examination.

RESULTS:

Mean particle diameter was between 61.57 ± 4.37 and 67.45 ± 8.13 μm, and mean encapsulation efficiency was between 60.20 ± 1.61 and 75.27 ± 1.60 %m/m. In vitro release experiment showed that the release time was over 30 days. The result of in vivo experiment showed that inflammatory reaction in the VA-PLGA intra-discal injection group was milder than the intravenous injection group (P < 0.05), also with less inflammation. The bacterial count was also significantly lower (1.02 × 10(3) ± 1.22 × 10(3) CFU/g) than the intravenous injection group (7.51 × 10(4) ± 7.16 × 10(4) CFU/g) (P < 0.05). Besides these data, the amount used in VA-PLGA intra-discal injection group is about 20 mg, and that used in the intravenous injection group is about 2.4 g. So, we just use 1/120 of VA i.v. to obtain the better results with our microparticles.

CONCLUSION:

Intra-discal injection with VA-PLGA sustained-release microspheres can use much less dosage, and effectively control and reduce infective discitis, and the therapeutic effect is superior to that of intravenous injection. A need for the clinical trials will be carried out in the near future.

• Authors: Fei Wang, Bin Ni, Zhuangchen Zhu, Fucun Liu, Yu-Zhao Zhu, Jun Liu
• Journal: Archives of orthopaedic and trauma surgery (Arch Orthop Trauma Surg) Vol. 131 Issue 1 Pg. 111-9 (Jan 2011) ISSN: 1434-3916 [Electronic] Germany
• PMID: 20661743 (Publication Type: Journal Article)

Chemical References

• Anti-Bacterial Agents
• Polyesters
• Polymers
• Lactic Acid
• poly(lactide)
• Vancomycin

Topics

• Animals
• Anti-Bacterial Agents (administration & dosage)
• Colony Count, Microbial
• Discitis (microbiology)
• Lactic Acid
• Methicillin-Resistant Staphylococcus aureus
• Microspheres
• Polyesters
• Polymers
• Rabbits
• Staphylococcal Infections
• Vancomycin (administration & dosage)