Is there a possibility to create a public key block cipher? Why there is no public key-based block cipher? It is known that the block ciphers are symmetric-key encryption. However, what is the motivation to not design a public key encryption that encrypts blocks of bits?
Let's make a list of reasons why public "block ciphers" are generally not used:


asymmetric ciphers expand the ciphertext compared to the plaintext, rather than being a permutation of a block of bits;
asymmetric ciphers require a lot more processing power;
asymmetric ciphers require a lot more state;
asymmetric ciphers are more vulnerable to side channel attacks (as they are based on big number arithmetic rather than binary operations on smaller words);
asymmetric ciphers are more vulnerable against attacks using quantum computers;
normal block cipher modes do generally not apply to asymmetric ciphers;
because of 2 &amp; 3, (full) hardware acceleration is generally less common for asymmetric ciphers.


I've left the word "generally" out of above reasons, but that may have to be inserted in each reason. There may be asymmetric ciphers that violate one or more of the rules displayed above.

Hybrid cryptography - where asymmetric / public cryptography is combined with symmetric / secret key cryptography - is rather easy to implement. So there is simply not much need for modes of encryption that use an asymmetric cipher for larger messages.

Modes such as ECIES or RSA-KEM are easy to describe and implement. Their main drawback is that the symmetric cipher mode of operation is generally not standardized.