The concept of nanoscale photonic jets has emerged as a novel way of focusing light with subwavelength spatial resolution. Practical focusing systems are, however, limited in their resolution by the multimodal structure of beams delivered by ∞exible waveguides or flbers. In this work, by using numerical modeling, we show that the chains of microspheres assembled inside the bores of the hollow waveguides or microcapillaries provide signiflcant advantages over single lenses in such applications. It is also shown that the chains of microspheres are capable of focusing light in contact with tissue. Experimental studies are performed for spheres with sizes from 10 to 300m with difierent indices of refraction ranging from 1.47 to 1.9. The focusing and transport properties of such chains are found to be in good agreement with numerical modeling results.