Long term multiple systemic antibiotics form the cornerstone in the treatment of bone and joint tuberculosis, often combined with local surgical eradication. implanted carriers for local drug delivery have recently been introduced to overcome some of the limitations associated with conventional treatment strategies. in this study, we used a calcium sulphate hemihydrate (cSH)/ nanohydroxyapatite (nHAP) based nanocement (NC) biomaterial as a void filler as well as a local delivery carrier of two standard of care tuberculosis drugs, Rifampicin (Rfp) and isoniazid (inH). We observed that the antibiotics showed different release patterns where INH showed a burst release of 67% and 100% release alone and in combination within one week, respectively whereas RFP showed sustained release of 42% and 49% release alone and in combination over a period of 12 weeks, respectively indicating different possible interactions of antibiotics with nHAP. The interactions were studied using computational methodology, which showed that the binding energy of nHAp with Rfp was 148 kcal/mol and INH was 11 kcal/mol, thus varying substantially resulting in RFP being retained in the nHAP matrix. Our findings suggest that a biphasic ceramic based drug delivery system could be a promising treatment alternative to bone and joint tB. Tuberculosis (TB) is a global disease that caused an estimated 1.2 million deaths in 2018 and around 10 million new TB cases were reported globally in the same year, with the incidence being stable in the recent years as per World Health Organization (WHO) report 1 Osteoarticular tuberculosis is a common manifestation accounting for 10-15% of all extrapulmonary TB (EPTB) 2,3 cases and 1-4% of all TB cases 4-6. The bone and joint TB is most often found in spine and weight bearing extremities resulting in neurological complications and joint destruction 7. Treatment modalities include surgical debridement of bone lesions, instrumental stabilisation and filling of dead space with allografts or autograft as well as systemic administration of anti-tuberculosis drugs (ATDs) like Isoniazid (INH), Rifampicin (RFP), Pyrazinamide (PZA), Ethambutol (EMB) and Streptomycin (SM). However, multiple drug resistance and TB recurrence has made it necessary to adhere to long-term, systemic oral use of multiple anti-tuberculosis drugs 8,9. Long-term systemic administration of first line drugs

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The molecular electrostatic potential (MESP) of the CS2 molecule, in conjunction with the cluster building algorithm, is utilized for generating trial geometries of medium-sized (CS2)n (n = 5-8) aggregates. MESP features suggest crossed, parallel stacked, T-shaped and L-shaped geometries for CS2 clusters. These initial geometries are subjected to geometry optimization employing second-order Møller-Plesset (MP2) theory, with correlation consistent aug-cc-pvDZ (aDZ) basis set. Single-point energies at MP2/aTZ levels are calculated for the estimation of binding energies at complete basis set (CBS) limit. The minimal nature of the reported structures is confirmed by doing vibrational frequency run at MP2/aDZ level of theory using the molecular tailoring approach (MTA). The two- and three-body interaction energies are computed for clusters with n = 5, 6, and 7 and these are suggestive of change in contact patterns with increasing n. Such an analysis is found to offer a qualitative explanation of the packing pattern found in the crystal structure.

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