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Chitosan/starch nanocomposites loaded with ampicillin were prepared using the spray-drying method by mixing various ratios of chitosan and starch. The morphology of chitosan/starch nanoparticles was studied using a scanning electron microscope (SEM), and the zeta potential value and size distribution were determined by a Nanoparticle Analyzer. The results show that the chitosan/starch nanocomposites have a spherical shape, smooth surface, and stable structure. Nanoparticle size distribution ranged from 100 to 600 nm, and the average particle size ranged from 300 to 400 nm, depending on the ratio between chitosan and starch. The higher the ratio of starch in the copolymer, the smaller the particle size. Zeta potential values of the nanocomposite were very high, ranging from +54.4 mV to +80.3 mV, and decreased from 63.2 down to +37.3 when loading with ampicillin. The chitosan/starch nanocomposites were also characterized by FT-IR to determine the content of polymers and ampicillin in the nanocomposites. The release kinetics of ampicillin from the nanocomposites were determined in vitro using an HPLC profile for 24 h. The loading efficiency (LE) of ampicillin into chitosan/starch nanoparticles ranged from 75.3 to 77.3%. Ampicillin-loaded chitosan/starch nanocomposites were investigated for their antibacterial activity against antibiotic-resistant Escherichia coli in vitro. The results demonstrate that the antibacterial effectiveness of nanochitosan/starch loading with ampicillin against E.coli was 95.41%, higher than the 91.40% effectiveness of ampicillin at the same concentration of 5.0 µg/mL after 24 h of treatment. These results suggest that chitosan/starch nanocomposites are potential nanomaterials for antibiotic drug delivery in the pharmaceutical field. [ABSTRACT FROM AUTHOR]

Well-known to be the most dynamic economic region in Vietnam with the establishment of more export processing zones, high technology parks, and industrial zones, the Southeast region is increasingly attracting more capital flows from all over the world. Does FDI inflow crowd in private investment in this region? To answer this research question, the study examines the effect of FDI inflow on private investment for a sample of 6 provinces/cities of the Southeast region between 2005 and 2019 using the panel quantile regression approach, the difference GMM Arellano-Bond, and the FE-IV estimator. The results show that FDI inflow crowds in private investment in this region. In addition, public expenditure, inflation, and population also promote private investment. These findings suggest some crucial policy implications for local governments in this region to receive more FDI inflows as well as promote private investment.

Fiscal deficits, the result of the government's fiscal policy in the direction of promoting economic growth and development, can be inflationary and cause social instability. Does the fiscal deficit – inflation relationship depend on the governance environment? To answer this question, the study uses the two-step difference GMM Arellano-Bond estimator to investigate the effects of fiscal deficit, governance, and their interaction on inflation for a sample of 34 developed countries with good governance environment and a sample of 86 developing countries with bad one from 2002 to 2019. The robustness of estimates is tested by the one-step difference GMM Arellano-Bond estimator. The estimated results show the fiscal deficit – inflation relationship strongly depends on the governance environment. Indeed, fiscal deficit and governance are deflationary in developed countries but inflationary in developing ones. In addition, public debt stimulates inflation in both two groups of countries. These findings suggest some important policy implications for governments in developing countries in reforming and improving the governance environment. [ABSTRACT FROM AUTHOR]