Research / 2020 / Article / Tab 1

Review Article

Smart Microneedles for Therapy and Diagnosis

Table 1

Fabrication strategies for microneedles and their potential applications.

StrategyExampleAdvantageLimitationApplication

Mold-based fabricationTypical four-step method [15, 1922]Accurate, reusable, able to generate multicomponent microneedles, suitable for massive production, easy to operateInflexible, nonuniversal, unavoidable drug loss, confined by the molds, including time-consuming and technology-dependent stepsThe most commonly used strategy, especially for massive production or industrial production
Modification via surface coating [3, 23]Simple, controllable, accurate, protective of bioactive cargos, suitable for massive production, easy to operateInflexible, nonuniversal, confined by the molds, including time-consuming and technology-dependent stepsA strategy based on a typical four-step method, applicable to carrying bioactive cargos
Mold filling by imprinting [24, 25]Accurate, protective of bioactive cargosInflexible, nonuniversal, unavoidable drug loss, confined by the molds, including time-consuming and technology-dependent steps, relying on extra equipmentA strategy based on a typical four-step method, applicable to carrying bioactive cargos
Mold filling by spin coating [26]Accurate, protective of bioactive cargosInflexible, nonuniversal, confined by the molds, including time-consuming and technology-dependent steps, relying on extra equipmentA strategy based on a typical four-step method, applicable to carrying bioactive cargos
Mold filling by infiltrating or spraying [27]Accurate, protective of bioactive cargosInflexible, nonuniversal, confined by the molds, including time-consuming and technology-dependent steps, relying on extra equipmentA strategy based on a typical four-step method, applicable to carrying bioactive cargos

Mold-free fabricationDrawing lithography [16, 17]Versatile, adjustable, economical, efficient, less-harmful, unrestricted by the molds, with simplified processes, with neglectable drug lossLacking accuracy, technology-dependent, only able to fabricate unilayer, cone-shaped microneedlesApplicable to carrying bioactive cargos
Droplet-born air blowing [18]Versatile, adjustable, mild, less-harmful, unrestricted by the molds, with simplified processes, with neglectable drug lossLacking accuracy, technology-dependent, only able to fabricate unilayer, cone-shaped microneedlesApplicable to carrying bioactive cargos
Centrifugal lithography [28]Versatile, adjustable, economical, mild, less-harmful, unrestricted by the molds, with simplified processesLacking accuracy, only able to fabricate unilayer, cone-shaped microneedlesApplicable to carrying bioactive cargos
3D printing [29]Accurate, unrestricted by the molds, suitable for elaborate synthesis, able to fabricate complicated patternsDependent on precision instrument, expensive, time-consumingSuitable for fabricating microneedles with complicated structures
Microlens-integrated technique [30]Inexpensive, mold-free, flexible, adjustable, scalable, automaticInvolving harmful steps, fastidious about microneedle materialsPotential in massive production or industrial production