Showing papers by "Lifeng Kang published in 2020"

Pharmaceutical Applications of 3D Printing

Abstract: Although 3D printing (3DP) has long been an integral part of industries such as aviation and automotive, its use in healthcare, especially the pharmaceutical industry, is relatively new and currently receiving close attention. At the beginning of 2018, we reviewed the applications of 3DP for drug delivery and drug testing [1]. Due to the rapid development of this field, it is necessary to summarize the latest development in this field after 2 years. In this article, we reviewed the three major areas in pharmaceutical applications. First, drug delivery system is the most studied subject, including controlled release, polypills, gastrofloating, orodispersibles and microneedles. Second, 3DP also helped the development of pharmaceutical devices, including pharmacy dispensing aids and drug eluting devices. Lastly, we reviewed the pharmaceutical models for drug testing, covering acellular and cellular models. We also summarized the materials used in the mentioned articles and their regulatory status for pharmaceutical applications to provide references for future research.

Geometrical optimisation of a personalised microneedle eye patch for transdermal delivery of anti-wrinkle small peptide.

Abstract: Acetyl-hexapeptide-3 (AHP-3) is a small peptide with good anti-wrinkle efficacy and safety profile. However, due to its hydrophilicity and high molecular weight, its skin permeation is generally poor. An innovative microneedle (MN) patch such as the curved, flexible or personalised MN patch is a viable avenue to deliver AHP-3. However, the well-researched geometrical relationship of MN on a flat MN patch cannot be assumed for these novel MN patches due to a complex mix of axial and shear forces. In this study, 3D printing was used for the fabrication of various MN patches with different MN geometries and curvatures. Both mechanical strength and skin penetration efficiency were used to determine the optimal MN geometry. The optimal MN geometry was then applied to the fabrication of a personalized MN patch (PMNP) for anti-wrinkle therapy, via 3D printing. In all, the general principles of MN geometrical effects on mechanical strength and skin penetration efficiency for a curved and a flat MN patch were similar. A MN height of 800 μm, tip diameter of 100 μm, interspacing of 800 μm and base diameter of 400 μm was observed to be the optimal MN geometry across all curvatures. In vitro skin permeation study demonstrated enhanced transdermal delivery of AHP-3 using the fabricated PMNP. Therefore, PMNP with optimized MN geometry can potentially be a novel approach to augment transdermal delivery of AHP-3 for effective wrinkle management.

rGO nanomaterial-mediated cancer targeting and photothermal therapy in a microfluidic co-culture platform

Abstract: We developed the microfluidic co-culture platform to study photothermal therapy applications. We conjugated folic acid (FA) to target breast cancer cells using reduced graphene oxide (rGO)-based functional nanomaterials. To characterize the structure of rGO-based nanomaterials, we analyzed the molecular spectrum using UV–visible and Fourier-transform infrared spectroscopy (FT-IR). We demonstrated the effect of rGO-FA-based nanomaterials on photothermal therapy of breast cancer cells in the microfluidic co-culture platform. From the microfluidic co-culture platform with breast cancer cells and human umbilical vein endothelial cells (HUVECs), we observed that the viability of breast cancer cells treated with rGO-FA-based functional nanomaterials was significantly decreased after near-infrared (NIR) laser irradiation. Therefore, this microfluidic co-culture platform could be a potentially powerful tool for studying cancer cell targeting and photothermal therapy.

Microneedles with Tunable Dissolution Rate.

Abstract: Dissolvable microneedle (MN) patches have been widely investigated for transdermal drug delivery. The dissolution rate of MN controls the status of drug release from the MN, which in turn determines drug absorption through skin. However, no systematic approaches have been reported to tune the dissolution profile of dissolvable MN matrices. This is the first study to show polyvinylpyrrolidone (PVP)-based dissolvable MN patches with varying dissolution profiles when PVP is copolymerized with cellulose materials. The MN patches were fabricated through thermal curing and photolithography in tandem. The various grades of pharmaceutical cellulose, such as hydroxypropyl methylcellulose and methyl cellulose, have been investigated as dissolution modifier incorporated in the MN patches. The resultant MN patches had dissolution profiles ranging from 45 min to 48 h. The dissolution rates varied with the grades of cellulose materials. Besides dissolution examination, the MN patches were characterized for their mechanical strength, moisture absorption, and skin penetration efficiency. All of the MN patches were able to penetrate the human skin in vitro. Overall, the PVP MN patches have great potential for skin applications as drug carriers with tunable dissolution profiles.

Development of a 3D-printed Medication Label for the Blind and Visually Impaired.

Abstract: This study explored the potential of three-dimensional printing (3DP) technology in producing a three-dimensional (3D) medication label for blind and visually impaired (BVI) patients to ease their drug administration. Different variations of label wordings, dosing instructions, and medication identifiers were designed with reference to guidelines by the American Foundation for the Blind. Shapes and symbols were used as dosing instructions and medication identifiers to the patient's medical conditions. Prototype designs were created with common graphics computer-assisted drafting software and 3D-printed using acrylonitrile butadiene styrene as the polymer filament. Feedback was then obtained from five people with normal vision and four BVI persons. The initial prototype comprised four components, namely, medication name and strength, patient's name, dosing instruction, and medication identifier. A revised label comprising the latter two components was developed after feedback by BVI persons. Words were in all uppercase and regular font type, with a 5-mm center-to-center letter spacing. Elevation heights of the letters alternated between 1 mm and 1.5 mm. A half sphere represented the medication dose unit, while vertical lines and a horizontal center line with alternating elevation of arrowheads represented the frequency of administration and the medication's consumption in relation to food, respectively. Symbols based on target organs were used as medication identifiers. With rapid advancements in 3DP technologies, there is tremendous potential for producing 3D labels in patients' medication management.

Enhanced skin permeation of a novel peptide via structural modification, chemical enhancement, and microneedles

Abstract: Hyperpigmentation is a common skin condition with serious psychosocial consequences. Decapeptide-12, a novel peptide, has been found to be safer than hydroquinone in reducing content of melanin, with efficacy up to more than 50% upon 16 weeks of twice daily treatment. However, the peptide suffers from limited transcutaneous penetration due to its hydrophilicity and large molecular weight. Therefore, decapeptide-12 was modified by adding a palmitate chain in an attempt to overcome this limitation. We also tested the effects of chemical penetration enhancers and microneedles to deliver two peptides through skin. Enhanced skin permeation was found using an in vitro human skin permeation model. Moreover, we examined peptide retention of different formulations in skin. Our data showed that palm-peptides in microneedle patch was the most effective.