Table 2.

Particulate systems evaluated in vitro as carriers of anti-tuberculosis drugs.

	Particulate System	Drug	Administration Scheme (Cell Line/Strategy)	Observations	Ref
NATURAL POLYMERS	Chitosan MPs	INH RFB	A549, THP-1 Mφ AI with Mb BCG	-Cell viability above 70% for A549 cells -Dose-dependent effect on THP-1 Mφ -Microencapsulation preserved antibacterial activity of drugs -Free and drug-loaded MPs induced increased secretion of TNF-α and IL-18 in THP-1 Mφ	[104]
	Chitosan NPs	Anti-Cystatin C siRNA	HMDM, THP-1 Mφ BI with Mtb H37Rv and susceptible and resistant isolates	-Loaded NPs were non-cytotoxic and were efficiently internalized by cells -Significant reduction in intracellular bacteria	[105]
	Fucoidan MPs	RFB INH	A549, THP-1 Mφ AI with Mb BCG	-Cell viability above 65% at 24 h -Encapsulation reduced RFB cytotoxicity -Free and loaded MPs induced TNF-α and IL-8 -Dose-dependent uptake of MPs	[106]
	Glucan NPs	RFB	J774 AI with Mtb H37Ra	-Induction of ROS and NO within infected Mφ -Induction of lysosome accumulation and phagolysosomal maturation in infected cells -The efficacy of RFB was enhanced 2.5-fold	[107]
SYNTHETIC POLYMERS	PLGA NPs	RIF	RAW 264.7, BMDM BI with Mb BCG	-Loaded NPs promoted the efficient clearing of BCG infection over a 12-day period	[108]
	PLGA NPs	RIF INHP	HMDM BI with Ms	-Sustained release of drugs over 15 days -Six-fold increase in therapeutic efficacy -Higher cell uptake and better antimicrobial activity than free drugs	[109]
	PLGA NPs encapsulated inside MAAEA MPs	RIF	Caco2, MH-S AI with Mtb H37Rv	-Loaded NPs translocated to the basolateral side of Caco2 cells and were not cytotoxic -Loaded and empty NPs decreased growth of intracellular bacteria	[110]
	Poly(ε-caprolactone)	INH SQ641 + CsA + VE	J774A.1 AI with Mtb H37Rv	-Better inhibition of intracellular replication of Mtb with SQ641-CsA-VE than SQ641 alone or INH	[111]
	Poly(ethylene sebacate) NPs	RIF-CUR	RAW 264.7 AI with Mtb H37Rv	-NPs were non-cytotoxic -Showed 1.5-fold higher drug internalization compared to free drugs -Significant killing of intracellular bacteria	[112]

NPs: nanoparticles; MPs: microparticles; PLGA: poly(lactic-co-glycolic) acid; MAAEA: methacrylic acid–ethyl acrylate copolymer; RIF: rifampicin; INHP: pentenyl–isoniazid; INH: isoniazid; SQ641 + CsA + VE: natural analogue of capuramycin + cyclosporine A + vitamin E; RFB: rifabutin; CUR: curcumin; BI: before infection; AI: after infection; BMDM: bone-marrow-derived monocytes; HMDM: human-monocyte-derived macrophages; Ms: Mycobacterium smegmatis; Mb: Mycobacterium bovis.