Electrospinning of PEGylated polyamidoamine dendrimer fibers

Spectroscopy, Morphology, and Electrochemistry of Electrospun Polyamic Acid Nanofibers

Polyamic acid (PAA) nanofibers produced by using the electrospinning method were fully characterized in terms of morphology and spectroscopy. A PAA nanofiber–modified screen-printed carbon electrode was applied to the detection of selected sulfonamides by following an electroanalytical protocol. The polyamic acid (PAA) nanofibers were characterized using Fourier transform infrared (FTIR) spectroscopy to study the integrity of polyamic acid functional groups as nanofibers by comparing them to chemically synthesized polyamic acid. A scanning electron microscope (SEM) was used to confirm the morphology of the produced nanofibers and 3D arrangement at the electrode interface. The Brunauer–Emmett–Teller (BET) method was used to determine the surface area of the nanofibers. Atomic force microscopy (AFM) was used to study the porosity and surface roughness of the nanofibers. Electrochemical evaluation based on diffusion-controlled kinetics was applied to determine the number of electrons transferred in the system, the surface concentration of the deposited PAA thin film (2.14 × 10⁻⁶ mol/cm²), and the diffusion coefficient (D_e) for the PAA nanofiber–modified screen-printed carbon electrode (9.43 × 10⁻⁷ cm⁻²/s). The reported LODs for sulfadiazine and sulfamethazine detection are consistent with requirements for trace-level monitoring by early warning diagnostic systems.

Ionic conductive nanocomposite based on poly(l-lactic acid)/poly(amidoamine) dendrimerelectrospun nanofibrous for biomedical application

The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out by blending with second-generation poly amidoamine (PAMAM) for enhancement of their ionic conductivity. The samples containing PLLA and various amounts of PAMAM (1%, 3%, 5%, and 7% by wt.) were fabricated by electrospinning techniques. The electrospun fibers were characterized using scanning electron microscopy (SEM), porosity, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry, contact angle measurement, water uptake measurement, mechanical properties, and electrical properties. Furthermore,in vitrodegradation study and cell viability assay were investigated in biomaterial applications. Creating amide groups through aminolysis reaction was confirmed by FTIR analysis successfully. The results reveal that adding PAMAM caused an increase in fiber diameter, crystallinity percentage, hydrophilicity, water absorption, elongation-at-break, and OE-mesenchymal stem cell viability. It is worth mentioning that this is the first report investigating the conductivity of PLLA/PAMAM nanofiber. The results revealed that by increasing the amount of PAMAM, the ionic conductivity of scaffolds was enhanced by about nine times. Moreover, the outcomes indicated that the presence of PAMAM could improve the limitations of PLLA like hydrophobicity, lack of active group, and poor cell adhesion.

Fast Dissolving Dendrimer Nanofiber Mats as Alternative to Eye Drops for More Efficient Antiglaucoma Drug Delivery

Polyamidoamine (PAMAM) dendrimers have been investigated as a potential platform for a number of ocular drugs, but only in aqueous solution. In this work we have developed fast dissolving dendrimer-based nanofibers (DNF) as a topical delivery vehicle for the glaucoma drug brimonidine tartrate (BT). The safety and drug release kinetics of these nanofiber mats were evaluated in vitro and in vivo. DNF caused no toxicity at therapeutic levels in cultured cells or ocular irritation in animal tests using a normotensive rat model. Intra-ocular pressure response was equivalent between DNF and BT solution in a single dose test, but DNF showed improved efficacy with daily dosing over a 3-week test period. This study indicates electrospun dendrimer nanofibers are a viable alternative to aqueous solutions as a more efficient method of administering antiglaucoma drug topically.