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We present a facile, low-cost and cleanroom-free technique for the fabrication of microneedles using molds created by laser ablation. Microneedle mold with high aspect ratios is achieved on acrylic sheet by engraving a specific pattern of crossover lines (COL) using CO2 laser cutter. Ablating COL pattern on the acrylic sheet creates a sharp conical shape in the center of the design. We have shown that a variety of microneedle shapes with different heights and tip angles can be easily achieved by changing the number and the length of the COL. Polydimethylsiloxane (PDMS) microneedles were fabricated by casting the PDMS on the mold. The resulted PDMS microneedles are oxygen plasma treated and then silanized. Another PDMS layer is casted on PDMS microneedles and detached after curing. The silanization prevents those two layers of PDMS from bonding to each other and makes them easily detachable. After detachment of the PDMS mold of microneedles, the mold is used to fabricate degradable polyvinyl alcohol microneedle patch suitable for transdermal drug delivery. The release kinetics of the needles are also shown and discussed in order to prove the applicability of the needles. A low-cost method to make microneedles for non-invasive drug delivery across the skin has been devised by a team in the United States. By forming microchannels in the skin, microneedles allow drugs such as insulin to be administered without a painful injection and with improved efficacy. However, conventional methods for fabricating microneedles are expensive, requiring cleanroom facilities. Sameer Sonkusale and co-workers at Tufts University have developed a method that does not require a cleanroom. They use a laser cutter to fabricate molds for microneedles in an acrylic sheet. The cone-shaped molds are created by passing the laser beam through the same point but by different paths, resulting in the greatest amount of material being removed from the central point. The researchers demonstrate their mold by making degradable microneedle patch from various polymers.

Chronic wounds are a major health concern and they affect the lives of more than 25 million people in the United States. They are susceptible to infection and are the leading cause of nontraumatic limb amputations worldwide. The wound environment is dynamic, but their healing rate can be enhanced by administration of therapies at the right time. This approach requires real-time monitoring of the wound environment with on-demand drug delivery in a closed-loop manner. In this paper, a smart and automated flexible wound dressing with temperature and pH sensors integrated onto flexible bandages that monitor wound status in real-time to address this unmet medical need is presented. Moreover, a stimuli-responsive drug releasing system comprising of a hydrogel loaded with thermo-responsive drug carriers and an electronically controlled flexible heater is also integrated into the wound dressing to release the drugs on-demand. The dressing is equipped with a microcontroller to process the data measured by the sensors and to program the drug release protocol for individualized treatment. This flexible smart wound dressing has the potential to significantly impact the treatment of chronic wounds.

Proficient antibiotic drug delivery plays a key role in treating infections. In this article we prepared an electrospun wound dressing which releases Tetracycline in a timed and dose controlled matter for one week. In order to fabricate a wound dressing which can release Tetracycline in a longer duration and at an effective therapeutic level we designed a bilayer electrospun patch made of polyvinyl alcohol (PVA), polycaprolacton (PCL), and coated the whole system with chitosan. The SEM micrograph showed the dependent relationship of the morphology of the nanofibers on the Tetracycline concentration, and the addition of PCL electrospun layer decreased the pore size and water uptake rate. However, it was found that coating PVA/PCL bilayered electrospun sheet with chitosan increased the water uptake rate, which is an important property in biomedical applications. According to the FTIR results, chemical composition of the scaffolds did not change during the fabrication process. Mechanical properties of the samples were assessed, and the results revealed that the chitosan coating improved the tensile strength of the electrospun layers. Furthermore, based on in vitro release tests, it was found that bilayered electrospun sheets coated with chitosan controlled drug release efficiently. In addition, the antibacterial tests performed in vitro showed stronger antibacterial activity on S. aureus cultures for PVA/PCL/Chitosan in comparison to uncoated samples.

Minoxidil and Rosemary essential oil have been used for several years to stimulate hair growth. Therefore, coadministration of both Minoxidil and Rosemary essential oil could enhance hair growth. The chemical/biological characteristics of liposomes, which encapsulate both hydrophobic and hydrophilic drugs, can be utilized to encapsulate the herbal and chemical drug concoction concomitantly. A thin-film hydration method was used to prepare the liposomes. The entrapment efficacy of the liposomes was determined for Minoxidil and Rosemary essential oil using UV spectrophotometry and hydrodistillation; as dictated in the European pharmacopeia. Furthermore, a dynamic light scattering (DLS) analysis was conducted to determine the particle size and zeta potential of the prepared liposome. In addition, the storage stability of the liposome was checked after 60 days. The results showed that coencapsulation of Minoxidil and Rosemary essential oil increased the encapsulation efficacy of Minoxidil while the entrapment efficacy of essential oil was not significantly influenced. In addition, according to the DLS results, the particle size and zeta potential of prepared liposomes didn’t change significantly during 60 days of storage.

SiO2-CaO-P2O5 based bioglass (BG) systems constitute a group of materials that have wide applications in bone implants. Chitosan (Cn) is a biocompatible and osteoconductive natural polymer that can promote wound healing. In this study, bioactivity of chitosan/bioglass (CnB) composites as minimally invasive bone regenerative materials was assessed both in vitro and in vivo. Injectability tests and scanning electron microscopy (SEM) results demonstrated the formation of uniform injectable paste-like composites using BG particles and Cn. Fourier transform infrared spectroscopy (FTIR) and SEM images confirmed hydroxyapatite deposition in vitro after incubation in simulated body fluid (SBF). Higher BG content in the composite correlated with increased human osteoblast proliferation. An in vivo study in a rat spinal fusion model confirmed that increasing the amount of BG improved osteoconductivity. Manual palpation, radiographic images and pathological assessments proved that the composites promote bone formation. Based on these data, the synthesized composites have a potential application in orthopedic and reconstructive surgeries as a minimally invasive bone substitute.