Preparation And Performance Of Bamboo Leaf Flavone Nanomicelles Based On Modified Sodium Ligninsulfonate

NM_LS/BLF/CSwas prepared by self-assembly in the system consisting of absolute ethanol and n-hexane,taking modified sodium lignosulfonate（LS/CTAB）as wall material,high purity C-glycoside flavonoid of bamboo leaf(the mass fraction of C-glycoside was above 70%,BLF₇₀)as core material and chitosan（CS）as decoloring agent.The structure and performance of NM_LS/BLF/CSwere tested,then its antioxidant property and UV absorbability of NM_LS/BLF/CSwere evaluated in vitro.The main conclusions are as follows.（1）NM_LS/BLF/CSwas prepared by self-assembly,taking modified sodium lignosulfonate（LS/CTAB）as wall material and BLF₇₀as core material.According to the single factor experiment and orthogonal experiment,the preparation parameters of NM_LS/BLFwere determined as follows:the concentration of LS/CTAB in ethanol was 3 g/L,the mass ratio of LS/CTAB to BLF₇₀was 10:1,the final concentration of n-hexane in self-assembly system was 35%and the flow rate of the constant flow pump was 700μL/s.At this time,the embedding rate was 80.57%.It was proved that micelle formation content（MFC）and micelle aggregation content（MAC）were linear with The logarithmic values of the initial concentration of LS/CTAB.Due to the dark color of sodium lignosulfonate,NM_LS/BLFwas brownish-yellow.To reduce its color,NM_LS/BLFwas added to 1%（w/w）of chitosan for decolorization,and NM_LS/BLF/CSwas obtained via vacuum freeze-drying process.NM_LS/BLF/CSis a kind of light yellow fluffy powder and uniformly,which is of 57.21 hunter whiteness,short resolution time,and stable solution after resolution.The potential of NM_LS/BLF/CSis-22.1±1.47 m V,the average particle size is 407.3±4.5 nm,and the dispersion coefficient（PDI）is0.351±0.006.（2）The chemical structural characterization of NM_LS/BLF/CSwas tested by UV and FTIR.The UV spectra of NM_LS/BLF/CSshowed typical I andⅡabsorption peaks of flavone.The FTIR spectra indicated the interaction between BLF₇₀and LS/CTAB,and BLF₇₀was embedded after self-assembly of LS/CTAB.The thermal stability of NM_LS/BLF/CSwas evaluated through DSC.It was showed that both the melting temperature and thermal enthalpy of NM_LS/BLF/CSincreased compared with LS/CTAB or BLF70,and NM_LS/BLF/CSshowed higher thermal stability.SEM image showed that NM_LS/BLF/CSwas spherical or ellipsoid.Also,NM_LS/BLF/CSshowed good storage stability.（3）The antioxidant experiments in vitro showed that NM_LS/BLF/CShad strong scavenging effect on superoxide anion free radicals,DPPH free radicals and ABTS free radicals,and also had significant reduction capability for Fe³⁺,which increased as the concentration.Compared with Trolox,NM_LS/BLF/CSshowed better superoxide anion free radical scavenging ability(IC₅₀=24.20μg/m L),DPPH free radical scavenging ability(IC₅₀=11.26μg/m L),ABTS free radical scavenging ability(IC₅₀=9.61μg/m L)and FRAP reducing ability（the value of FRAP was 528.25μmol/L at the concentration of 40μg/m L）.The scavenging rates of NM_LS/BLF/CSto DPPH free radicals and ABTS free radicals continued to increase with time,indicating that NM_LS/BLF/CSwas slow-release antioxidant with long-term antioxidant effects.（4）The results of sunscreen performance of NM_LS/BLF/CSwere as follows:the SPF value of the sunscreen lotion and the growth rate of SPF value increased as the concentration of BLF₇₀or NM_LS/BLF/CS.When the addition was 7.5%,the SPF value of the sunscreen lotion containing NM_LS/BLF/CSwas 2.6 times that of BLF₇₀.NM_LS/BLF/CScombined with physical UV filters（Zn O and Ti O₂）,chemical UV filters（OMC and BMDM）,respectively.The SPF values of the sunscreen lotion were obtained.The results showed that:the SPF value of sunscreen lotion increased by45.76%and 82.04%respectively after the combination of NM_LS/BLF/CSwith Zn O and Ti O₂.SPF value of the formula increased by 8.21%%and 14.01%after the combination with OMC and BMDM,which meant NM_LS/BLF/CScan partially replace the use of physical and chemical UV filters to achieve high sun protection factor value.Due to the photo-resistance of LS/CTAB,the sun protection performance of NM_LS/BLF/CScould be maintained for 8 h under UV radiation,which meant NM_LS/BLF/CScould provided long-lasting sunscreen performance.In conclusion,modified sodium lignin-based bamboo flavonoids nano micelle(NM_LS/BLF/CS)is a composite bio-nanomaterial with natural components and stable properties.It is a kind of cosmeceutical with long-lasting and significant antioxidant property,broad-spectrum and high-efficiency UV absorbability.NM_LS/BLF/CSis cost-effective,has the potential as a new sunscreen functional factor,and has a good application prospect in daily chemical products.