Tetracycline-loaded calcium phosphate nanoparticle (Tet-CPNP): Rejuvenation of an obsolete antibiotic to further action.
Increasing resistance in bacteria towards antibiotics has made it imperative to research on their revitalization to combat infectious diseases. This study dealt with synthesis of a nano-form of the antibiotic tetracycline, its characterization and potency of killing different multi-drug resistant diarrhea-causing bacteria.



Nano-formulation was done by loading tetracycline within biocompatible calcium phosphate nanoparticle. The synthesized tetracycline-loaded calcium phosphate nanoparticle (Tet-CPNP) was characterized by the techniques like TEM, DLS, EDS, FTIR, spectrofluorimetry and dialysis. Bactericidal activity of nano-particulate tetracycline was investigated by agar plating, spectrophotometry, phase contrast-fluorescence-atomic force microscopy and flow cytometry techniques.



The Tet-CPNPs were 8±5nm in size and nearly spherical in shape, efficiency of tetracycline loading in CPNP was about 20% and the release of antibiotic from Tet-CPNPs was sustainable during 7days. Minimum inhibitory concentration (MIC) of Tet-CPNP on multiple antibiotic (including tetracycline) resistant bacteria like Escherichia coli, Salmonella kentuckey and Shigella flexneri was in the range of 20-40μg/ml, whereas MIC of free tetracycline was in the range of 150-180μg/ml. NP-mediated cell filamentation and cell membrane disintegration caused cell killing. Moreover, death of Shigella-infected Zebra fish larvae was stalled by Tet-CPNP treatment. CPNP itself had no toxic effect on bacteria as well as on Zebra fish.



Our nano-formulation of tetracycline might reclaim a nearly obsolete antibiotic to further potential function.



Such a study on revival of an old, cheap, broad-spectrum antibiotic to further action is highly beneficial to developing countries with limited health care budgets.
Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741 235, West Bengal, India.
Riya
R
Mukherjee
Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741 235, West Bengal, India.
Mousumi
M
Patra
Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741 235, West Bengal, India.
Debanjan
D
Dutta
Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741 235, West Bengal, India.
Milon
M
Banik
Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741 235, West Bengal, India. Electronic address: tarakdb@yahoo.com.
Tarakdas
T
Basu
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D002130:Calcium Phosphates / Q000008:administration & dosage*; D002462:Cell Membrane / Q000187:drug effects / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D007814:Larva / Q000187:drug effects / Q000382:microbiology; D053758:Nanoparticles / Q000008:administration & dosage*; D010316:Particle Size; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012060:Rejuvenation / Q000502:physiology; D013752:Tetracycline / Q000494:pharmacology*; D015027:Zebrafish / Q000382:microbiology
D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; D011500:Protein Synthesis Inhibitors; C020243:calcium phosphate; D013752:Tetracycline
Calcium phosphate nanoparticle; Diarrhea-causing multi-drug resistant bacteria; MIC; Tetracycline; Zebra fish