Design Principles for Triggerable Polymeric Amphiphiles with Mesogenic Side Chains for Multiscale Responses with Liquid Crystals

Interfacial assemblies formed by polymeric amphiphiles at aqueous interfaces of thermotropic liquid crystals (LCs) can trigger multiscale changes in the organization of the LCs in response to recognition events. However, we have a limited understanding of the rules governing the rational design of LC-integrated polymeric amphiphiles. Herein, we report the synthesis of families of amphiphilic polymers that differ in (i) side-chain molecular structure, (ii) polymer architecture, and (iii) copolymer composition. We used this library in experiments to establish structure–property relationships relevant to the design of multifunctional polymers that can amplify and transduce biomolecular recognition events into optically detectable, macroscopic ordering transitions in LCs. We then utilized these structure–property relationships to guide the design of a peptide–polymer amphiphile (PPA) that assembles at the interface of LC droplets. Enzymatic cleavage of PPA-coated LC droplets by thermolysin directly triggered a change in the internal ordering of the LC within the droplets and the scattering of light from the droplets. The results of our study provide important guidance to future designs of triggerable LC systems

Effects of cattle saliva on cellulose degradation.

<p>(a) Enhancement effect of cattle saliva. Effect of cattle saliva addition on the production of reducing sugar from micro-crystalline cellulose. Reaction mixtures containing 10 μg/mL cellulase and 0.8% (wt%) cellulose were incubated in the presence or absence of 10% cattle saliva at 50°C for 24 h. Effects of (b) cellulase concentration, (c) incubation time and (d) cattle saliva concentration on reducing sugar production. In (b), concentrations of cellulase used were 0, 1, 5, 10, 50, 100, 500 and 1000 μg/mL, while the concentration of cellulose was kept same as in (a) above and the reaction mixtures were incubated at 50°C for 24 h. In <b>(c),</b> different incubation times were used (0, 1, 3, 6, 12, 24, 48 and 72 h) while keeping the composition of the reaction mixture same as in (a) above. In (d), different concentrations of cattle saliva were used here: 0, 0.5, 1, 2, 3, 4, 7 and 10%; concentrations of cellulase and cellulose and reaction conditions were same as in (a) above. All experiments were performed in triplicate and results are expressed as average means. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).</p

Effect of various treatments on the enhancement effect of cattle saliva.

<p>(a) Denatured and dialyzed cattle saliva. Denaturation of cattle saliva: Cattle saliva was autoclaved for 13 minites at 121°C to denature proteins. After that, the saliva was centrifuged at 20,400 x <i>g</i> for 10 min. The supernatant (called ‘Autoclaved saliva’) was collected and subsequently used in experiments. Dialysis of cattle saliva: Cattle saliva was dialyzed against distilled water for 72 h at room temperture. The water was exchanged every other day. (b) Proteinase K treatment. Twenty microliters cattle saliva was mixed with 20 μL proteinase K (20 mg/mL) and the mixture was incubated at 50°C for 12 h. After the incubation, the mixture was incubated at 96°C for 10 min to denature proteinase K. This mixture was called ‘Proteinase K Saliva’ and used in the cellulose degradation assay. The concentration of cattle saliva in the reaction mixture was 5%. All experiments were performed in triplicate and average mean values were plotted. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).</p

Properties of cattle saliva on real biomass degradation.

<p>Effects of (a) cellulase concentration and (b) incubation time on cellulose conversion. (a) Cellulase concentrations were 0, 10, 50, 100 and 250 μg/mL, while concentration of cattle saliva was constantly 10%. The reaction mixtures were incubated at 50°C for 24 h. (b) Different incubation times were tested (0, 12, 24, 48 and 72 h), while concentrations of cellulase and cattle saliva were constantly 50 μg/mL and 10%, respectively. The reaction mixtures were incubated at 50°C. All experiments were performed in triplicate and average mean values were plotted. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).</p

Removal of protein in cattle saliva.

<p>(a) Protein concentration in cattle saliva treated with methanol or acetone. Protein concentration was measured using Bradford protein assay. (b) Enhancement effect of cattle saliva treated with methanol or acetone. Cattle saliva treated with methanol or acetone used in the cellulose degradation assay. The reaction condition follows the basic experimental protocol. All experiments were performed in triplicate and average mean values were plotted. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).</p

Addition order assay.

<p>(a) Schematic representation of the experimental design. (b) Effect on the production of reducing sugar. The amount of reducing sugar produced at each addition order experimental condition, shown schematically in (a), was measured. Simultaneous: A mixture in which cellulose, cellulase and cattle saliva were added simultaneously. Added with cellulase: Cellulase was added to a mixture containing cellulose and cattle saliva. Added with cellulose: Cellulose was added to a mixture containing cellulase and cattle saliva. Added with saliva: Cattle saliva was added to a mixture containing cellulose and cellulase. Simultaneous (25 hours): A mixture in which cellulose, cellulase and cattle saliva were added simultaneously and incubated for 25 h. Error bars indicate ± standard deviations (n = 9). Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).</p

Adsorption analysis of cattle saliva proteins.

<p>Adsorption of cattle saliva proteins to cellulose was analyzed using (a) SDS-PAGE and (b) Bradford protein assay. (a) SDS-PAGE analysis. Lane 1: Cattle saliva solution (80%). Lane 2: Supernatant, supernatant after the mixture was incubated at 50°C for an hour. Lane 3: Wash 1, supernatant of Wash buffer 1. Lane 4: Wash 2, supernatant of Wash buffer 2. Lane 5: Wash 3, supernatant of Wash buffer 3. Lane 6: Elute, eluted fraction after the cellulose pellet was mixed with 0.5% SDS and incubated at 96°C for 1 h. (b) Amount of protein in each sample used for SDS-PAGE analysis was quantified by Bradford protein assay. Error bars indicated ± deviations (n = 3).</p

Crystal structure analysis of cellulose.

<p>The crystal structure of cellulose in the presence of cattle saliva (Saliva(+)) or in the absence of cattle saliva (Saliva(-)) was analyzed by (a) X-ray diffraction and (b) FT-IR.</p

Distribution and metabolism of ¹⁴C-sulfoquinovosylacylpropanediol (¹⁴C-SQAP) after a single intravenous administration in tumor-bearing mice

<p></p><p>Sulfoquinovosylacylpropanediol (SQAP) is a novel potent radiosensitizer that inhibits angiogenesis in vivo and results in increased oxigenation and reduced tumor volume. We investigated the distribution, metabolism, and excretion of SQAP in male KSN-nude mice transplanted with a human pulmonary carcinoma, Lu65.</p><p>For the metabolism analysis, a 2 mg (2.98 MBq)/kg of [glucose-U-¹⁴C]-SQAP (CP-3839) was intravenously injected. The injected SQAP was decomposed into a stearic acid and a sulfoquinovosylpropanediol (SQP) in the body.</p><p>The degradation was relatively slow in the carcinoma tissue.1,3-propanediol[1-¹⁴C]-SQAP (CP-3635) was administered through intravenous injection of a 1 mg (3.48 MBq)/kg dose followed by whole body autoradiography of the mice.</p><p>The autoradiography analysis demonstrated that SQAP rapidly distributed throughout the whole body and then quickly decreased within 4 hours except the tumor and excretion organs such as liver, kidney.</p><p>Retention of SQAP was longer in tumor parts than in other tissues, as indicated by higher levels of radioactivity at 4 hours. The radioactivity around the tumor had also completely disappeared within 72 hours.</p><p></p> <p>Sulfoquinovosylacylpropanediol (SQAP) is a novel potent radiosensitizer that inhibits angiogenesis in vivo and results in increased oxigenation and reduced tumor volume. We investigated the distribution, metabolism, and excretion of SQAP in male KSN-nude mice transplanted with a human pulmonary carcinoma, Lu65.</p> <p>For the metabolism analysis, a 2 mg (2.98 MBq)/kg of [glucose-U-¹⁴C]-SQAP (CP-3839) was intravenously injected. The injected SQAP was decomposed into a stearic acid and a sulfoquinovosylpropanediol (SQP) in the body.</p> <p>The degradation was relatively slow in the carcinoma tissue.1,3-propanediol[1-¹⁴C]-SQAP (CP-3635) was administered through intravenous injection of a 1 mg (3.48 MBq)/kg dose followed by whole body autoradiography of the mice.</p> <p>The autoradiography analysis demonstrated that SQAP rapidly distributed throughout the whole body and then quickly decreased within 4 hours except the tumor and excretion organs such as liver, kidney.</p> <p>Retention of SQAP was longer in tumor parts than in other tissues, as indicated by higher levels of radioactivity at 4 hours. The radioactivity around the tumor had also completely disappeared within 72 hours.</p