225
1. Calibrate the calorimeter with pure indium (T m = 156.6 °C)
before analyses, by applying a single heating cycle, and check
the characteristic transition temperature T m and enthalpy change
ΔH to be within specifications.
2. Obtain the DSC thermogram of each sample by utilizing any
appropriate DSC calorimeter.
3. Include for each analysis a 10-min isotherm at 20 °C (see Note
12), two heating-cooling cycles between 20 and 60 °C, and a
final heating process from 20 °C to 60 °C (see Notes 13 and
14), at a scanning rate of 5 °C min
−1
(see Note 15), under constant nitrogen gas flow rate of 50 mL min
−1
(see Note 16).
1. Analyze the obtained calorimetric data by using the software
installed in the calorimeter.
2. Select the desired heating or cooling cycle to analyze (see Note
17). In this case, choose the first and second heating scan, as
well as the first cooling scan (see Note 18).
3. Normalize each sample analysis per weight/moles of total sample, lipid, or polymer (see Note 19).
4. Choose the desired thermodynamic parameters for each thermodynamic phenomenon, i.e., endothermic or exothermic.
These are the characteristic transition temperatures T onset and T,
enthalpy change ΔH, and width at half peak height of the C p
profiles ΔT 1/2 .
5. During peak integration, manually set the baseline carefully.
The profiles of all samples containing DPPC bilayers with incorporated thermoresponsive amphiphilic block copolymers PNIPAMb- PLA 1 or 2 are presented in Fig. 2.
The following observations can be made on the
thermograms:
∙ Incorporation occurs and the copolymers alter the thermotropic behavior of DPPC bilayers in a concentration- and
composition- dependent effect, where increasing amounts of
the same polymer lead to main transition temperature T m
(41.8 °C) elevation and ΔΗ m reduction during the first heating
cycle. As a result, the lyotropic effect of the polymers is evident
and the higher T m values are associated with a new metastable
functional/thermoresponsive phase, which is created on the
membrane when the PLA segment is incorporated inside the
membrane, with the PNIPAM groups extending outside to
form a hydrophilic corona.
3.3 DSC Analysis
3.4 DSC Profile
and Thermodynamic
Parameter Extraction
3.5 DSC Profile
Analysis of the
Thermoresponsive
Chimeric Systems
Thermodynamics and Functionality of Thermoresponsive Chimeric Nanosystems
1. Calibrate the calorimeter with pure indium (T m = 156.6 °C)
before analyses, by applying a single heating cycle, and check
the characteristic transition temperature T m and enthalpy change
ΔH to be within specifications.
2. Obtain the DSC thermogram of each sample by utilizing any
appropriate DSC calorimeter.
3. Include for each analysis a 10-min isotherm at 20 °C (see Note
12), two heating-cooling cycles between 20 and 60 °C, and a
final heating process from 20 °C to 60 °C (see Notes 13 and
14), at a scanning rate of 5 °C min
−1
(see Note 15), under constant nitrogen gas flow rate of 50 mL min
−1
(see Note 16).
1. Analyze the obtained calorimetric data by using the software
installed in the calorimeter.
2. Select the desired heating or cooling cycle to analyze (see Note
17). In this case, choose the first and second heating scan, as
well as the first cooling scan (see Note 18).
3. Normalize each sample analysis per weight/moles of total sample, lipid, or polymer (see Note 19).
4. Choose the desired thermodynamic parameters for each thermodynamic phenomenon, i.e., endothermic or exothermic.
These are the characteristic transition temperatures T onset and T,
enthalpy change ΔH, and width at half peak height of the C p
profiles ΔT 1/2 .
5. During peak integration, manually set the baseline carefully.
The profiles of all samples containing DPPC bilayers with incorporated thermoresponsive amphiphilic block copolymers PNIPAMb- PLA 1 or 2 are presented in Fig. 2.
The following observations can be made on the
thermograms:
∙ Incorporation occurs and the copolymers alter the thermotropic behavior of DPPC bilayers in a concentration- and
composition- dependent effect, where increasing amounts of
the same polymer lead to main transition temperature T m
(41.8 °C) elevation and ΔΗ m reduction during the first heating
cycle. As a result, the lyotropic effect of the polymers is evident
and the higher T m values are associated with a new metastable
functional/thermoresponsive phase, which is created on the
membrane when the PLA segment is incorporated inside the
membrane, with the PNIPAM groups extending outside to
form a hydrophilic corona.
3.3 DSC Analysis
3.4 DSC Profile
and Thermodynamic
Parameter Extraction
3.5 DSC Profile
Analysis of the
Thermoresponsive
Chimeric Systems
Thermodynamics and Functionality of Thermoresponsive Chimeric Nanosystems